Sustainable Highway Construction Guidebook (2019)

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50 C H A P T E R 9 Sustainable Construction Practices Project Delivery Level 9.1 Project Delivery Method Overview The project delivery method defines the process and contractual arrangement by which a proj- ect is designed, constructed, and (sometimes) financed, operated, and maintained. The approach used to deliver a highway project can affect sustainability efforts, typically making them easier or harder to accomplish depending upon the context. The most common forms of project delivery are: design-bid-build (DBB), DB, and construction management at risk (CMR), also known as construction manager/general contractor (CM/GC). Sustainability efforts in project delivery generally encourage delivery methods that allow better integration of design and construction. Motivations Business Opportunity X Project Requirement X Goodwill Sustainable Construction Practices • Early inclusion of sustainability objectives. Allows sustainability to be fully integrated into project objectives and measured outcomes as opposed to a later addition that may require extra work for inclusion. • Contractor input in design phase. Allows early accesses to the contractor’s expertise on sustainable solutions. Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Related Categories

Sustainable Construction Practices 51 Effort (time and cost): 1.9 Impact/Effort Ratio Human Welfare: 3.0 Environmental Benefit: 3.3 Cost Savings: 2.5 4.7 Effort (time and cost): 2.7 Impact/Effort Ratio Human Welfare: 2.0 Environmental Benefit: 2.1 Cost Savings: 3.3 2.8 Principal Guidance, Assistance, and Tools Molenaar, K., C. Harper, and I. Yugar-Arias. 2014. Guidebook for Selecting Alternative Contracting Methods for Roadway Projects: Project Delivery Methods, Procurement Procedure, and Payment Provisions. Transportation Pooled Fund Program. TPF-5(260) Study. University of Colorado, Boulder, Colorado. Minchin, R. E., Jr., G. C. Migliaccio, K. Atkins, et al. 2016. NCHRP Report 787: Guide for Design Management on Design-Build and Construction Manager/ General Contractor Projects. Transportation Research Board of the National Academies of Sciences, Engineering, and Medicine, Washington, D.C. FHWA. 2018. TechBrief: Alternative Contracting Method Performance in U.S. Highway Construction. FHWA-HRT-17-100. Washington, D.C. 9.1.1 Early Inclusion of Sustainability Objectives Summary Early inclusion of sustainability objectives in a project life-cycle is more effective than later in the process because it may affect the selection of a project delivery method. Moreover, sus- tainability objectives, if included early as a meaningful part of the project objectives, can guide the development of alternative designs, materials options, and the methods by which these are evaluated. For instance, environmental criteria may be evaluated beyond just regulatory compliance, life-cycle costing may be used in place of first costs, or specific accommodations may be made for issues of special concern to neighbors or workers. Guidance on general project development is plentiful, but guidance on integrating sustainability into the process is still minimal. Key Reference Armstrong, A., L. M. Reid, A. J. Davis, and J. Gault. 2013. An Integrated Approach for Building Sustainable Roads. FHWA-WFL/TD-13-002. Western Federal Lands Highway, Vancouver, Washington. 9.1.2 Contractor Input in Design Phase

52 Sustainable Highway Construction Guidebook Summary Multiple project delivery methods can provide contractor input on the design phase. The most appropriate one depends upon project context. DB, CM/GC, and integrated project delivery (IPD)—also known as alliance contracting— are delivery methods that allow for early contractor involvement in the project design phase. This can (1) bring additional expertise to bear on sustainability issues and (2) improve construc- tability and related sustainability benefits such as safety, reduced waste, and shorter schedule. Under DB, a single contracted entity provides both design and construction services. A survey study in the State of Colorado showed that on average DB delivery method for highway con- struction reduces the overall duration of the projects by 14 percent and reduces the total cost of the projects by 3 percent while maintaining the same level of quality in comparison to the traditional DBB delivery method (Dornan et al., 2006). Under CM/GC, the designer and the contractor operate under separate contracts with the agency. However, the agency selects a contractor early, so that it can provide input during the design phase. On a $1.5 million road restoration project in Fond du Lac, Minnesota, savings of $150,000 in engineering costs were credited to the contractor input in the CM/GC contract (Longley and Davies, 2012). Under IPD, the agency, designer, contractor, and other project entities enter into a multi- party contractual agreement. This agreement aligns all parties with common group goals, which can include sustainability. While U.S. agencies only use IPD for building projects, it has been used internationally for transportation projects. Key References Minchin, R. E., Jr., G. C. Migliaccio, K. Atkins, et al. 2016. NCHRP Report 787: Guide for Design Management on Design-Build and Construction Manager/General Contractor Projects. Transportation Research Board of the National Academies, Washington, D.C. FHWA. 2006. Design-Build Effectiveness Study. FHWA, Washington, D.C. Prepared by SAIC, AECOM Consult, and University of Colorado at Boulder. Longley, W., and M. Davies. 2012. Construction Manager/General Contractor Project Case Study: Construction Manager/General Contractor Method Hastens Delivery of Critical Bridge for Fond du Lac Reservation. FHWA-14-CAI-022. Washington, D.C. Gransberg, D. D., E. Scheepbouwer, and M. C. Loulakis. 2015. NCHRP Synthesis 466: Alliance Contracting–Evolving Alternative Project Delivery. Transportation Research Board of the National Academies, Washington, D.C. Allison, M., H. Ashcraft, R. Cheng, et al. 2018. Integrated Project Delivery: An Action Guide for Leaders. Main sponsors: Charles Pankow Foundation, Center for Innovation in the Design and Construction Industry and Integrated Project Delivery Alliance. Dornan, D., K. Molenaar, N. Macek, and J. Shane. 2006. Design-Build Effectiveness Study—As Required by TEA-21 Section 1307(f): Final Report. FHWA, U.S. DOT, Washington, D.C.

Sustainable Construction Practices 53 9.2 Financing Overview Funding for highway construction has been traditionally provided by public sources. How- ever, some agencies are using a variety of private financing mechanisms to meet growing fund- ing needs for which there is insufficient political will to address through taxes and other more traditional public funding sources. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity X Project Requirement X Goodwill Effort (time and cost): 3.6 Impact/Effort Ratio Human Welfare: 2.1 Environmental Benefit: 1.6 Cost Savings: 2.8 1.8 Motivations Sustainable Construction Practices • Public-private partnership (PPP). Contractual agreement between public/private sector partners that allows more private sector participation than usual including financing, con- structing, owning, and operating facilities. Principal Guidance, Assistance, and Tools Titus-Glover, L., D. Raghunathan, S. Sadasivam, et al. 2016. Guidebook on Financing of Highway Public-Private Partnership Projects. FHWA-HIN-17-003. Office of Innovative Program Delivery, FHWA, Washington, D.C. 9.2.1 Public-Private Partnership (PPP) Summary The U.S. DOT’s report to congress on PPPs in 2004 defines PPP as “. . . a contractual agree- ment formed between public and private sector partners, which allow more private sector partici- pation than is traditional. The agreements usually involve a government agency contracting with a private company to renovate, construct, operate, maintain, and/or manage a facility or system.

54 Sustainable Highway Construction Guidebook While the public sector usually retains ownership in the facility or system, the private party will be given additional decision rights in determining how the project or task will be completed.” A PPP represents a different way of financing than the traditional 100% government-financed project. Because private sector financing partners are included, PPPs can alter traditional highway construction goals to ones that may be more sustainable. For instance, PPPs can finance projects beyond available public funds, shift cost thinking to a life-cycle approach, introduce nontraditional private entity values into a project, and perhaps deliver projects sooner and for less money. For instance, some private entities have stockholder or other mandates for sustainable investment, which may motivate them to push for sustainability features and/or sustainability rating system certifica- tion. More directly, the Sustainability Accounting Standards Board standards for construction ser- vices companies contains a metric that requires reporting the “number of (1) commissioned projects certified to a multi-attribute sustainability standard and (2) active projects seeking such certification.” Key References FHWA. 2018. Center for Innovative Finance Support. Public Private Partnerships (P3). https://www.fhwa.dot.gov/ipd/p3. Accessed September 2018. Jenkins, B., L. Amini, K. deMello, et al. 2019. NCHRP Synthesis 540: Leveraging Private Capital for Infrastructure Renewal. Transportation Research Board of the National Academies, Washington, D.C. Parsons Brinkerhoff, Nossaman LLP, and HS Public Affairs. 2015. Effect of Public-Private Partnerships and Nontraditional Procurement Processes on Highway Planning, Environmental Review, and Collaborative Decision Making. SHRP 2 Report S2-C12-RW-1.

Sustainable Construction Practices 55 Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity X Project Requirement X Goodwill Motivations Principal Guidance, Assistance, and Tools Molenaar, K., C. Harper, and I. Yugar-Arias. 2014. Guidebook for Selecting Alternative Contracting Methods for Roadway Projects: Project Delivery Methods, Procurement Procedure, and Payment Provisions. Transportation Pooled Fund Program. TPF-5(260) Study. University of Colorado, Boulder, Colorado. Scott, S., K. R. Molenaar, D. D. Gransberg, and N. C. Smith. 2006. NCHRP Report 561: Best-Value Procurement Methods for Highway Construction Projects. Transportation Research Board of the National Academies, Washington, D.C. 9.3 Procurement Overview Procurement is the process of purchasing the external services and materials necessary to deliver a project. The timeline for procuring services affects project budgeting. Moreover, selecting an appropriate procurement method based on project needs could result in a reduc- tion in project cost and also lead to purchase of services and goods that address environmental and human needs. The approach used to deliver a transportation project affects the overall sustainability of the project, including its construction. Related Categories Sustainable Construction Practices • Include sustainability in best-value procurement. Consider quantitative and qualitative sustainability practices as a selection criterion in best-value procurement. • Include life-cycle costs in best-value procurement. Consider life-cycle costs of the highway, rather than just initial construction costs, as a selection criterion in best-value procurement. • Value engineering during procurement: alternative technical concept (ATC). Include sus- tainability enhancements as a criterion considered in ATC proposals. • Sustainable procurement rules. Procurement process that accounts for multiple sustain- ability dimensions (cost, environment, and human well-being) in establishing what must be considered in purchasing.

56 Sustainable Highway Construction Guidebook Key References Scott, S., K. R. Molenaar, D. D. Gransberg, and N. C. Smith. 2006. NCHRP Report 561: Best-Value Procurement Methods for Highway Construction Projects. Transportation Research Board of the National Academies, Washington, D.C. Minnesota DOT Office of Construction and Innovative Contracting. 2012. Best-Value Procurement Manual. St. Paul, Minnesota. Effort (time and cost): 3.1 Impact/Effort Ratio Human Welfare: 1.4 Environmental Benefit: 1.9 Cost Savings: 3.4 2.1 9.3.2 Include Life-Cycle Costs in Best-Value Procurement Effort (time and cost): 2.1 Impact/Effort Ratio Human Welfare: 3.1 Environmental Benefit: 3.5 Cost Savings: 2.3 4.1 9.3.1 Include Sustainability in Best-Value Procurement Summary Best-value procurement (BVP) considers both qualitative and quantitative criteria for select- ing project contractors and vendors. Criteria can be selected to require or reward sustainable construction practices and/or experience. Sustainability criteria could include (1) proposer’s experience with sustainable construction; (2) proposed sustainable highway construction fea- tures that address project sustainability objectives; (3) achievement of sustainability rating system certification; (4) measurement and/or achievement of key sustainability metrics like greenhouse gas (GHG) emissions, fuel use reduction, or local hiring; and (5) consideration of life-cycle costs rather than just construction costs. Projects specifically calling out sustainability as a criterion in BVP have typically done so by soliciting (1) a contractor description of their sustainable practices, (2) certification in using a sustainability rating system, (3) a description of environmental compliance actions, or (4) individual sustainability accreditation. The use of BVP varies in the United States; several DOTs have produced manuals on their approach or included BVP in their standard procurement manuals. Gransberg, D. D., M. C. Loulakis, and G. M. Gad. 2014. NCHRP Synthesis 455: Alternative Technical Concepts for Contract Delivery Methods. Transportation Research Board of the National Academies, Washington D.C. FHWA. 2017. Procurement, Management, and Administration of Engineering and Design Related Services—Questions and Answers. https://www.fhwa.dot.gov/ programadmin/172qa.pdf.

Sustainable Construction Practices 57 Summary Traditionally, highway project cost estimation focuses on initial construction and related costs (preliminary engineering, right-of-way, and construction administration) only. Choices of materials and systems are made based on adherence to minimum standards and lowest price. However, it is often more appropriate to determine the total cost of ownership of a highway sys- tem (for instance, a stormwater system) and use that information, rather than first cost, to select the system. The total cost of ownership, known best as the life-cycle cost, is most appropriately calculated by using published standards to create a fair evaluation. However, not all systems have such standards. Examples of some that do are pavements, bridges, and stormwater systems. Life-cycle cost analysis (LCCA) is the process of comparing the life-cycle costs of two or more alternatives, and is used by most state DOTs in some form, usually for pavement type decision- support on larger projects. Importantly, LCCA only compares differential costs, and assumes that the benefits of competing alternatives are the same. This may be an acceptable assumption for some highway systems, such as pavement, but may be inappropriate for others, such as certain stormwater systems that provide different benefits. Key References Walls III, J., and M. R. Smith. 1998. Life-Cycle Cost Analysis in Pavement Design— Interim Technical Bulletin. FHWA-SA-98-079. FHWA, U.S. DOT, Washington, D.C. Hawk, H. 2003. NCHRP Report 483: Bridge Life-Cycle Cost Analysis. Transportation Research Board of the National Academies, Washington, D.C. Taylor, S., M. Barrett, M. Leisenring, et al. 2014. NCHRP Report 792: Long-Term Performance and Life-Cycle Costs of Stormwater Best Management Practices. Transportation Research Board of the National Academies, Washington, D.C. FHWA. n.d. Life-Cycle Cost Analysis. Office of Asset Management, Pavements and Construction. https://www.fhwa.dot.gov/infrastructure/asstmgmt/lcca.cfm. Effort (time and cost): 3.1 Impact/Effort Ratio Human Welfare: 2.5 Environmental Benefit: 2.7 Cost Savings: 3.5 2.8 9.3.3 Value Engineering during Procurement: Alternative Technical Concept (ATC) Summary According to FHWA, “Alternative Technical Concepts (ATC) are suggested changes sub- mitted by proposing teams to the contracting agency’s supplied basic configurations, project scope, design or construction criteria. These proposed changes provide a solution that is equal to or better than the requirements in the Request for Proposal document. If the ATC concept is acceptable to the contracting agency, the concept may be incorporated as part of the propos- ing team’s technical and price submittal. ATCs provide flexibility to the proposers in order to enhance innovation and achieve efficiency.”

58 Sustainable Highway Construction Guidebook Effort (time and cost): 2.2 Impact/Effort Ratio Human Welfare: 2.7 Environmental Benefit: 3.1 Cost Savings: 1.7 3.4 Key References FHWA. 2017. Alternative Technical Concepts. http://www.fhwa.dot.gov/ construction/cqit/atc.cfm. Gransberg, D. D., M. C. Loulakis, and G. M. Gad. 2014. NCHRP Synthesis 455: Alternative Technical Concepts for Contract Delivery Methods. Transportation Research Board of the National Academies, Washington D.C. 9.3.4 Sustainable Procurement Rules Summary Sustainable procurement is a purchasing process that accounts for not only economic but also environmental and social considerations. Many organizations and industries have devel- oped standard procurement rules that emphasize and even enforce sustainable procurement. The FHWA Green Procurement Guide, although somewhat dated (2010), provides guidance on “green purchasing” (essentially, using sustainability’s environment dimension as a purchasing criterion) for the U.S. DOT. It provides guidance on what must be considered when purchasing the following: • Energy Star products identified by DOE and EPA as well as the Federal Energy Management program designated energy-efficient products, • Recycled content products (EPA’s Comprehensive Procurement Guidelines), • Environmentally preferable products, • Water-efficient products (EPA’s WaterSense standards), • Energy from renewable sources, • Bio-based products (USDA Bio-Preferred program), • Alternative fuel vehicles and alternative fuels (Energy Policy Act), • Products with low or no toxic or hazardous constituents, and • Non-ozone depleting substances (identified in EPA’s Significant New Alternative Program). Considerations are generally written to emphasize or give preference to more sustainable choices. Key Reference FHWA. 2010. FHWA Green Procurement Guide. https://www.fhwa.dot.gov/ legsregs/directives/orders/gppg041910.htm. ATCs are, essentially, value engineering in the procurement phase. ATCs are generally used to save money, save time, or reduce risk. In best-value procurement they may also improve the proposer’s evaluation on non-financial criteria. ATCs can also be used to enhance project sustainability if the owner includes sustainability enhancements as an evaluation criterion. For instance, an ATC on a highway interchange could reconfigure the interchange to avoid sensitive area land takes, thus reducing its ecological impact.

Sustainable Construction Practices 59 Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity X Project Requirement X Goodwill 9.4 Contracting Overview Contracting is the process of establishing a legally enforceable agreement expressing the expectations, responsibilities, and protections of each party for services and materials. This agreement and the process for developing it can be used to allow, require, or incentivize sustainable highway construction practices. Related Categories Motivations Sustainable Construction Practices • Value engineering during construction: value engineering change proposal (VECP). Include sustainability as a criterion for evaluating VECP. • Use of a sustainability rating system. Provides a set of sustainability best practices and a method to evaluate their completion. May also provide the contractor some choice in sustain- able practices to pursue. • Indefinite delivery/indefinite quantity (IDIQ) contract. IDIQ contracts can streamline the procurement process where multiple contracts of a similar nature are involved. • Sustainability management plan. Provides a means to articulate sustainability goals and commitments; and a way to track, manage, and report on their accomplishments. Principal Guidance, Assistance, and Tools Molenaar, K., C. Harper, and I. Yugar-Arias. 2014. Guidebook for Selecting Alternative Contracting Methods for Roadway Projects: Project Delivery Methods, Procurement Procedure, and Payment Provisions. Transportation Pooled Fund Program. TPF-5(260) Study. University of Colorado, Boulder, Colorado. FHWA. 2017. Procurement, Management, and Administration of Engineering and Design Related Services—Questions and Answers. https://www.fhwa.dot.gov/ programadmin/172qa.pdf.

60 Sustainable Highway Construction Guidebook Muench, S. T., J. Koester, C. Croft, et al. 2011. Best Management Practices for Sustainable Road Design and Construction. FHWA-WFL/TD-11-004. Vancouver, Washington. Ashuri, B., and H. Kashani. 2012. Recommended Guide for Next Generation of Transportation Design Build Procurement and Contracting in the State of Georgia. FHWA-GA-12-1023. Georgia DOT, Forest Park, Georgia. 9.4.1 Value Engineering During Construction: Value Engineering Change Proposal (VECP) Effort (time and cost): 2.5 Impact/Effort Ratio Human Welfare: 1.8 Environmental Benefit: 1.8 Cost Savings: 3.0 2.7 Summary The FHWA defines value engineering (VE) “. . . as a systematic process of review and analysis of a project, during the concept and design phases, by a multidiscipline team of persons not involved in the project, that is conducted to provide recommendations for: 1. providing the needed functions safely, reliably, efficiently, and at the lowest overall cost; 2. improving the value and quality of the project; and 3. reducing the time to complete the project.” These concepts are part of sustainability. However, sustainability itself can be added as an item to review in the VE process. While formal VE analysis is required by regulation on the concept/design of federal-aid projects of $50 million or more ($40 million or more for bridges), a similar process, called a value engineering change proposal (VECP), can be used during the construction phase of a project (enabled by a contract clause). Rather than a formal review, a VECP program addresses how contractor ideas and resulting cost savings can be proposed and incorporated into a project. Owners often provide incentives to contractors for VECP ideas in the form of a split of the resulting savings (often 50/50). Contractors submit their ideas as VECPs for approval by the agency. If approved, the proposal is incorporated into the design and the contract (by formal change order). It may be necessary to allow the contractor and owner extra time to analyze the project and provide useful VECPs or similar-type changes for design-build projects. Washington State DOT has used what they call a “practical pause,” which is a time set aside where Washington State DOT and the contractor can meet in a design review and discuss potential changes to the project that reduce cost, shorten schedule, or lower risk. This “practical pause” concept can work for both DBB and DB project deliveries. Key Reference FHWA. 2017. Value Engineering Change Proposals (VECPs). https://www.fhwa. dot.gov/construction/cqit/vecp.cfm.

Sustainable Construction Practices 61 Effort (time and cost): 2.3 Impact/Effort Ratio Human Welfare: 0.5 Environmental Benefit: 0.5 Cost Savings: 1.0 0.9 9.4.2 Use of a Sustainability Rating System Effort (time and cost): 2.2 Impact/Effort Ratio Human Welfare: 3.5 Environmental Benefit: 3.5 Cost Savings: 1.4 3.9 Summary A sustainability rating system is a list of sustainability best practices with an associated com- mon metric, usually points. Contracts can require the use, pursuit, and/or achievement of a sustainability rating system outcome (e.g., a certification level). Rating systems can be advanta- geous because they already describe an array of sustainable practices that can be individually specified, or a point/rating/certification level can be specified and the contractor can be given some choice in which sustainable practices are achieved to attain the point/rating/certification level. Rating systems tend to focus on the large idea of roadway sustainability and therefore contain credits that go beyond just construction. Nonetheless, they usually have a subset of credits that directly address the construction process. There are several rating systems appli- cable to highway construction in the United States, most notably FHWA’s INVEST (an entirely voluntary self-evaluation system for roadways), Greenroads (a third-party rating system for roadways), and Envision (a third-party rating system for infrastructure). Key References INVEST v1.3. www.sustainablehighways.org. Greenroads Rating System, v2. 2018.02.23. www.greenroads.org. Envision v3. www.sustainableinfrastructure.org. 9.4.3 Indefinite Delivery/Indefinite Quantity (IDIQ) Contract Summary According to the Federal Acquisition Regulation (FAR), Indefinite Delivery/Indefinite Quan- tity (IDIQ) contracts provide for an indefinite quantity of supplies or services during a fixed period and within stated limits. IDIQ contracts can streamline contract bids and award pro- cesses where multiple contracts are anticipated by consolidating procurement actions to one transaction instead of many. For example, FHWA’s Office of Federal Lands Highway uses IDIQ contracts for a variety of ongoing construction work including 2007 through 2009 Going-to- the-Sun Road rehabilitation work in Glacier National Park under which they issued 19 projects worth over $86 million to the IDIQ prime contractor. IDIQ contracts can be appropriate for all delivery methods and can help improve response times in emergency situations by allowing an owner to quickly issue work orders without going through a complete procurement process (Gransberg et al., 2015).

62 Sustainable Highway Construction Guidebook Key References Gransberg, D. D., J. A. R. Benavides, and M. C. Loulakis. 2015. NCHRP 473: Synthesis Indefinite Delivery/Indefinite Quantity Contracting Practices. Transportation Research Board of the National Academies, Washington, D.C. FHWA Notice. 2018. Indefinite Delivery and Indefinite Quantity Contracts for Federal-Aid Construction. Federal Register, Vol. 83(85), pp. 19393–19395. 9.4.4 Sustainability Management Plan Effort (time and cost): Impact/Effort Ratio Human Welfare: Environmental Benefit: Cost Savings: Not RatedNot Rated This SCP was added after the rating process was complete, so it is not rated. Summary This is a written plan to manage sustainability. Construction-focused sustainability manage- ment plans are still rare in the highway construction industry but may emerge as a reasonable way to consolidate and document contractor sustainability requirements, efforts, and results. Section 6.6 describes sustainability management plans in more detail and provides a template to assist in creating them. Key References None.

Sustainable Construction Practices 63 Project Level 9.5 Scheduling Overview A construction schedule provides a plan for completing a project accounting for space, time, and resource constraints, and dependencies between constriction activities. Shorter and more efficient construction schedules may reduce user costs and environmental impacts, while more flexible schedules can maximize contractor efficiencies. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity X Project Requirement X Goodwill Motivations Sustainable Construction Practices • Accelerated construction. Reduce construction time to reduce associated user delay. • Flexible start dates. Allowing the contractor to better allocate its resources and time could result in more efficient and faster project delivery that satisfies the public. • Full road closure. Fully closing a highway (one or both directions) to improve worker pro- ductivity and safety, and reduce overall construction time. Principal Guidance, Assistance, and Tools FHWA. n.d. Accelerated Construction Technology Transfer. https://www.fhwa.dot. gov/construction/accelerated/index.cfm. Caltrans. n.d. R3-CA4PRS Implementation Project for Rapid Rehabilitation. http:// www.dot.ca.gov/hq/research/roadway/llprs/index.htm. 9.5.1 Accelerated Construction Effort (time and cost): 2.9 Impact/Effort Ratio Human Welfare: 3.2 Environmental Benefit: 2.7 Cost Savings: 2.2 2.8

64 Sustainable Highway Construction Guidebook Summary This process accelerates a construction schedule to reduce overall user delay. User delay can be a major contributor to overall project financial impact, especially in congested urban areas where the cost of work zone user delays can be high. Reducing user delay by accelerat- ing construction can be incentivized in contracting. The major impacts of doing this are (Fick et al., 2010): • Cost. Accelerated construction generally costs more because contractors typically spend more to achieve an incentive. Therefore, achieving the incentive is important to the profit- ability of the project. • Contract time measurement. If payment is linked to faster completion, contract time measurement and adjustments for excusable delays have added importance. • Staffing. Accelerated construction generally requires more working hours per day every week, which contributes to mental and physical fatigue. • Quality. Incentives for construction speed may compromise quality if time must be sacrificed for quality. • Safety. While safety standards may not be compromised for construction speed, staff fatigue should be considered. Reduced construction time also reduces worker exposure and may contribute to improved safety. Accelerated construction is typically measured against a baseline determined by the owner. Faster contractor construction may be a result of an owner-offered incentive or it may be more of an illusion based on a conservative baseline set by the owner. This section addresses A+B bidding, lane/ramp rentals or charges, and incentives/disincentives. But there are other similar methods for the owner to communicate to the contractor the willingness to pay a premium for accelerated construction. A+B bidding. This is a bidding method that places a cost on the duration of a project or por- tion of a project. An A+B bid contains the contract price (item A) as well as a time to complete the contract. This time is converted to a monetary value (item B) and the overall bid is evaluated as the total cost of the contract plus the time cost (A+B). Sometimes the B component is dependent upon the total time certain lanes or ramps are closed or inaccessible. This method places value on project duration and/or lane/ramp closure times (which impact roadway user costs), which often results in (1) shorter project durations than estimated by the owner, and (2) somewhat higher costs than those associated with a standard schedule (Minchin, 2016). A+B bidding is more impactful where user delay is a major cost and works best with an associated incentive/ disincentive clause based on actual construction duration and/or lane/ramp closure times versus the contractor’s promise in the bid. Lane/ramp rentals or charges. This is a bidding method where charges for closing a lane or ramp are established by the owner and the charges for closing lanes and/or ramps are deducted from contractor revenues. Typically, either the contractor is paid for an estimated lane rental amount and then the actual lane rental is deducted from revenues, or lane/ramp rental or charges can be included as a contract pay item (Fick et al., 2010). Incentives and disincentives to reduce construction time. Contractual incentives and disincentives are commonly used to encourage early project completion and minimize user delay cost. Standard practice usually involves (1) incentives to finish early and (2) dis- incentives (penalties or liquidated damages) for finishing late. Typically, contractors spend extra to achieve incentives, so incentives should not be viewed as purely profit, but rather additional money provided to cover required expenses (and appropriate profit) to reduce construction time.

Sustainable Construction Practices 65 Key References Fick, G., E. T. Cackler, S. Trost, and L. Vanzler. 2010. NCHRP Report 652: Time- Related Incentive and Disincentive Provisions in Highway Construction Contracts. Transportation Research Board of the National Academies, Washington, D.C. Anderson, S. D., and J. S. Russell. 2001. NCHRP Report 451: Guidelines for Warranty, Multi-Parameter, and Best Value Contracting. Transportation Research Board of the National Academies, Washington, D.C. Texas DOT. 2018. Accelerated Construction Guidelines. Austin, Texas. Minchin, R. E., and A. R. Chini. 2016. Alternative Contracting Research. Contract Number BDV31-977-40. Florida DOT, Tallahassee, Florida. 9.5.2 Flexible Start Dates Effort (time and cost): 1.8 Impact/Effort Ratio Human Welfare: 1.7 Environmental Benefit: 1.2 Cost Savings: 2.3 2.9 Summary This is a contract provision that allows the contractor to choose the construction start date within given limits. For instance, the Florida DOT normally requires a contractor to begin work within 15 days of the notice to proceed (NTP), but with a flexible start date this time may be extended (usually up to 100 days). A flexible start date can allow the contractor to more efficiently use workforce, equipment, and subcontractors over a variety of projects; and it may also increase bid competition as more contractors may be able to accommodate the work within their schedules (FHWA, 2002). Owner requirements to coordinate multiple projects and other factors may limit flexible start options. Key References FHWA. 2002. Technical Advisory: FHWA Guide for Construction Contract Time Determination Procedures. Washington, D.C. https://www.fhwa.dot.gov/ construction/contracts/t508015.cfm. Accessed September 2018. Washington State DOT. 2018. Flexible Start Date. http://www.wsdot.wa.gov/ Projects/delivery/alternative/FlexibleStart.htm. Caltrans. 2017. Construction Manual. Section 3-803B. MCT 17-1. Sacramento, California. Effort (time and cost): 1.5 Impact/Effort Ratio Human Welfare: 2.1 Environmental Benefit: 1.3 Cost Savings: 2.3 3.7 9.5.3 Full Road Closure

66 Sustainable Highway Construction Guidebook Summary Fully closing a highway (one or both directions) for rehabilitation or maintenance eliminates the direct exposure of motorists to the work zone and workers to live traffic. This can improve construction productivity and quality, reduce project duration, save money, and improve motorist and worker safety (FHWA, 2003). Surveys of the public tend to show strong support for full closures for fewer days when compared to partial closures or night work for many more days (FHWA, 2003). Software tools, namely CA4PRS (available to all 50 State DOTs through the FHWA), can help estimate the impacts of full road closures compared to more traditional closures on construction productivity and total user delay. Key References FHWA. 2018. Road Closure and Lane Closure. https://ops.fhwa.dot.gov/wz/ construction/full_rd_closures.htm. FHWA. 2003. Full Road Closure for Work Zone Operations: A Cross-Cutting Study. https://ops.fhwa.dot.gov/wz/resources/publications/FullClosure/CrossCutting/its.htm. FHWA. 2008. CA4PRS Software, December 19, 2008 FHWA-Endorsed Technology and Free Group-license for All 50 State DOTs. https://www.fhwa.dot.gov/ construction/ca4prsbroc.cfm.

Sustainable Construction Practices 67 9.6 Estimating Overview Estimating is the prediction of construction costs. In this section, estimating addresses the general process by which construction costs are estimated and what might be considered in an estimate. Sustainable estimating practices usually involve the use of technology to improve efficiency and accuracy, including the use of life-cycle costs/benefits in product selection. While it may be fairly straightforward to estimate the cost of an SCP, benefits are often non-monetary and difficult to quantify. In a sense, the whole process of evaluating sustainable practices is to give proper consideration to those benefits that are not readily monetized. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity X Project Requirement X Goodwill Motivations Sustainable Construction Practices • Model-based estimation. Model-based estimation techniques provide precise quantities and better tracking and repeatability of estimates. They can also connect estimates with other electronic construction processes. • Use of life-cycle costs. Better decisions can be made by considering the total cost of infra- structure over its life-cycle by accounting for initial construction, maintenance, operations, and end-of-life. Principal Guidance, Assistance, and Tools Walls III, J., and M. R. Smith. 1998. Life-Cycle Cost Analysis in Pavement Design- Interim Technical Bulletin. FHWA-SA-98-079. FHWA, Washington, D.C. Anderson, S., K. Molenaar, and C. Schexnayder. 2007. NCHRP Report 574: Guidance for Cost Estimation and Management for Highway Projects During Planning, Programming, and Preconstruction. Transportation Research Board of the National Academies, Washington, D.C. Turochy, R. E., L. A. Hoel, and R. S. Doty. 2001. Highway Project Cost Estimating Methods Used in The Planning Stage of Project Development. VTRC 02-TAR3. Virginia Transportation Research Council, Charlottesville, Virginia.

68 Sustainable Highway Construction Guidebook 9.6.1 Model-Based Estimation Effort (time and cost): 2.9 Impact/Effort Ratio Human Welfare: 0.5 Environmental Benefit: 0.9 Cost Savings: 2.8 1.4 Summary Conventional estimation techniques heavily rely on manual approaches and can be prone to inaccuracies. In contrast, model-based estimation techniques use a high-quality model synchro- nized with the building information modeling (BIM) for improved estimation of quantities to support a reliable project cost. Additionally, model-based estimation techniques are flexible, as the model can be easily updated in case of changes to the original design or project schedule (Bylund and Magnusson, 2011). Key References Lu, Q., J. Won, and J. C. Cheng. 2016. A Financial Decision-Making Framework for Construction Projects Based on 5D Building Information Modeling (BIM). International Journal of Project Management, Vol. 34(1), pp. 3–21. Bylund, C., and A. Magnusson. 2011. Model Based Cost Estimations-An International Comparison. Division of Construction Management, Lund University, Sweden. 9.6.2 Use of Life-Cycle Costs Effort (time and cost): 3.0 Impact/Effort Ratio Human Welfare: 1.6 Environmental Benefit: 2.1 Cost Savings: 3.4 2.4 Summary Traditionally, highway project cost estimation focuses on initial construction and related costs (preliminary engineering, right-of-way, and construction administration) only. Choice of materials and systems is made based on adherence to minimum standards and lowest price. However, it is often more appropriate to determine the total cost of ownership of a highway sys- tem (for instance, a stormwater system) and use that information, rather than first cost, to select the system. The total cost of ownership, known best as the life-cycle cost, is most appropriately calculated by using published standards to create a fair evaluation. However, not all systems have such standards. Examples of some that do are pavements, bridges, and stormwater systems. Life-cycle cost analysis (LCCA) is the process of comparing the life-cycle costs of two or more alternatives, and is used by most state DOTs in some form, usually for pavement type decision- support on larger projects. Importantly, LCCA only compares differential costs, and assumes that the benefits of the competing alternatives are the same. This may be an acceptable assump- tion for some highway systems, such as pavement, but may be inappropriate for others, such as certain stormwater systems that provide different benefits.

Sustainable Construction Practices 69 Key References Walls III, J., and M. R. Smith. 1998. Life-Cycle Cost Analysis in Pavement Design- Interim Technical Bulletin. FHWA-SA-98-079. FHWA, Washington, D.C. Hawk, H. 2003. NCHRP Report 483: Bridge Life-Cycle Cost Analysis. Transportation Research Board of the National Academies, Washington, D.C. Taylor, S., M. Barrett, M. Leisenring, et al. 2014. NCHRP Report 792: Long-Term Performance and Life-Cycle Costs of Stormwater Best Management Practices. Transportation Research Board of the National Academies, Washington, D.C. FHWA. n.d. Life-Cycle Cost Analysis. Office of Asset Management, Pavements and Construction. https://www.fhwa.dot.gov/infrastructure/asstmgmt/lcca.cfm.

70 Sustainable Highway Construction Guidebook 9.7 Project Controls/Administration Overview Project controls and administration are processes used to ensure a timely and on-budget project delivery and allow key personnel to make informed decisions using the most current data available. This usually constitutes an information management system and personnel that provide input to and run the system. Project controls and administration affect project eco- nomics through impacts to cost, schedule, and materials. Improvements are often associated with efficiency gains and new abilities made possible by more automation, computer, and cloud integration. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Motivations Business Opportunity X Project Requirement X Goodwill Sustainable Construction Practices • Enhanced information technology (IT). Use of enhanced IT to improve efficiency and capabilities. • Geomatics. The discipline of collecting and using geographic or spatial data. Principal Guidance, Assistance, and Tools FHWA. 2018. FHWA e-Construction Program. https://www.fhwa.dot.gov/construction/ econstruction. (This section is almost entirely addressed by proprietary software and hardware available for purchase, or in-house-developed systems.) 9.7.1 Enhanced Information Technology (IT) Effort (time and cost): 2.8 Impact/Effort Ratio Human Welfare: 1.8 Environmental Benefit: 1.3 Cost Savings: 2.1 1.8

Sustainable Construction Practices 71 Summary Enhanced IT includes the adoption of multimedia tools, messaging services, voice-based tools, and mobile or wearable devices. e-Construction, a joint FHWA–AASHTO effort, aims to promote “. . . the collection, review, approval, and distribution of highway construction contract documents in a paperless environment” (e-Construction, FHWA website). While this concept is comprehensive, the idea of “enhanced IT” goes beyond making exist- ing processes paperless and aims to develop better processes that create more value from ever-increasing amounts of data and connectivity. For example, a contemporary mobile phone’s capabilities provide much more value than just enhancement of a land-line phone’s calling features. Most organizations have a piecemeal rather than a systematic approach to enhanced IT: different systems are used for different purposes and full integration is not possible. Some pro- cesses, such as signatures and distribution of plans, are more likely to be IT-enhanced while others, such as inspection records, are less likely. There is a general belief in the importance of mobile devices (AASHTO annual surveys from 2012 to 2016 noted an increase from 59% to 79% amongst DOTs), while legacy systems continue to be upgraded or replaced. Issues with enhanced IT include: legacy system upgrade costs, change management (approach to prepare and manage the change to more advanced IT solutions within an organization), data security (more current IT solutions require data to reside outside an organization, for instance, on Ama- zon AWS or Microsoft Azure), and ownership. Key Reference Shah, K., A. Mitchell, D. Lee, and J. Mallela. 2017. Addressing Challenges and Return on Investment (ROI) for Paperless Project Delivery (e-Construction). FHWA-HIF-17-028. FHWA, Office of Infrastructure Research and Technology, McLean, Virginia (basic review of the state-of-practice and method for implementing technologies and calculating their return on investment). 9.7.2 Geomatics Effort (time and cost): 2.8 Impact/Effort Ratio Human Welfare: 0.9 Environmental Benefit: 0.9 Cost Savings: 2.1 1.4 Summary Geomatics is the discipline of gathering, storing, processing, and displaying geographic or spatially referenced information. It includes systems that leverage global positioning systems (GPS), geographic information systems (GIS), light detection and ranging (LIDAR), barcod- ing, radio frequency identification (RFID), and more. For example, Maryland State Highway Administration (MDSHA) successfully field tested the tracking of HMA placement in parking lots and new pavements by placing encapsulated RFID tags inside the delivered mix (Schwartz et al., 2014). NCHRP Report 748 (Olsen et al., 2013) provides guidelines for the use of mobile LIDAR in transportation projects including highway construction applications like machine control, as-built documentation, quality control, and quantity measurement (see Section 14.4 of NCHRP Report 748).

72 Sustainable Highway Construction Guidebook Key References Olsen, M. J., G. V. Roe, C. Glennie, et al. 2013. NCHRP Report 748: Guidelines for the Use of Mobile LIDAR in Transportation Applications. Transportation Research Board of the National Academies, Washington, D.C. (covers all transportation uses of LIDAR, construction is just one section). Schwartz, C. W. 2014. Radio Frequency Identification Applications in Pavements. FHWA-HRT-14-061. FHWA, Office of Infrastructure Research and Development, McLean, Virginia (detailed review of research using RFID in pavement materials tracking).

Sustainable Construction Practices 73 9.8 Drainage/Sewer/Water Overview Drainage, sewer, and water all address water infrastructure on the project. Regulatory requirements addressing these topics are extensive. Therefore, sustainability opportunities in these areas are fewer than in other areas. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Motivations Business Opportunity Project Requirement X Goodwill Sustainable Construction Practices No viable SCPs were identified in this area.

74 Sustainable Highway Construction Guidebook 9.9 Earthwork Overview Most roadway construction involves some earthwork (moving of soil mass from one location to another). Earthwork can represent significant project expenses, leading most projects to mini- mize earthwork where practical. Sustainable earthwork practices generally involve minimizing equipment and haul vehicle operations, which minimizes fuel use, vehicle operating costs, and associated emissions. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity X Project Requirement X Goodwill Motivations Sustainable Construction Practices • Balanced earthwork. Balancing cut and fill to reduce earthwork hauling and associated fuel use and emissions. • Ground improvement for construction. Techniques used to improve geotechnical charac- teristics of ground that would otherwise be unsuitable for construction. • Trenchless drainage renewal. Drainage renewal methods that avoid open-cut trenches and thus eliminate trenches in the traveled lanes and reduce equipment use and associated fuel use and emissions. Principal Guidance, Assistance, and Tools Nazarian, S., M. Mazari, I. N. Abdallah, et al. 2015. Modulus-Based Construction Specification for Compaction of Earthwork and Unbound Aggregate. Transportation Research Board of the National Academies, Washington, D.C. TRB. n.d. Transportation Earthworks: Information Resource Center. http://www.trb.org/AFS10/AFS10.aspx. 9.9.1 Balanced Earthwork Effort (time and cost): 2.0 Impact/Effort Ratio Human Welfare: 1.2 Environmental Benefit: 3.2 Cost Savings: 3.1 3.8

Sustainable Construction Practices 75 Summary Balancing cut and fill within a project generally reduces hauling operations because no material needs to be imported or removed from the job site. Projects that involve substantial earthwork can benefit greatly from balanced earthwork. In projects with limited earthwork (for example, a pavement overlay), balanced earthwork has very little impact. GPS-enabled technologies used in combination with model-based designs that use automated machine guidance can support efficient and optimized earthwork operations (Kim et al., 2015; Ji et al. 2010). Key References Ji, Y., F. Seipp, A. Borrmann, et al. 2010. Mathematical Modeling of Earthwork Optimization Problems. In Proceedings of the International Conference on Computing in Civil and Building Engineering. Kim, H., Z. Chen, C.-S. Cho, et al. 2015. Integration of BIM and GIS: Highway Cut and Fill Earthwork Balancing. Computing in Civil Engineering, pp. 468–474. Townes, D. 2013. Automated Machine Guidance with Use of 3D Models. FHWA-HIF-13-054. FHWA, Tech Brief. 9.9.2 Ground Improvement for Construction Effort (time and cost): 2.7 Impact/Effort Ratio Human Welfare: 1.0 Environmental Benefit: 2.8 Cost Savings: 1.8 2.1 Summary In situations where the ground features make construction infeasible, various ground improvement techniques are employed to improve the ground conditions for construction. General categories of ground improvement are (Schaefer et al., 2016): 1. Vertical drains and accelerated consolidation: PVDs with and without fill preloading; 2. Lightweight fills: compressive strength fills and granular fills; 3. Deep compaction: deep dynamic compaction and vibro-compaction; 4. Aggregate columns: stone columns and rammed aggregate piers; 5. Column-supported embankments: reinforced soil load transfer platform, non-compressible columns, and compressible columns; 6. Soil mixing: deep mixing and mass mixing; 7. Grouting: chemical, compaction, jet, rock fissure, bulk void filling, and slab-jacking; 8. Pavement support stabilization: mechanical, chemical, and moisture control; 9. Reinforced soil structures: reinforced soil walls, reinforced soil slopes, and soil nail walls. It may be that in some cases the energy and emissions associated with a ground improvement process could exceed those associated with a remove-and-replace option. In such cases, there may be negligible environmental benefit to ground improvement, but economic (lower cost) or human welfare (for example, less traffic delay or construction disruption for project neighbors) benefits may still warrant the method.

76 Sustainable Highway Construction Guidebook 9.9.3 Trenchless Drainage Renewal Key References FHWA. 2017. Ground Improvement. https://www.fhwa.dot.gov/engineering/ geotech/improvement/index.cfm. Schaefer, V. R., R. R. Berg, G. J. Collin, et al. 2016. Ground Modification Methods- Reference Manual Volume I. FHWA-NHI-16-027. Geotechnical Engineering Circular No. 13. National Highway Institute, Washington, D.C. Effort (time and cost): 2.5 Impact/Effort Ratio Human Welfare: 1.9 Environmental Benefit: 3.3 Cost Savings: 2.1 2.8 Summary Traditional drainage renewal methods can require significant open-cut surface excavation. Trenchless methods can provide several advantages: (1) reduce traffic disruption by removing active construction from traveled lanes; (2) reduce earthwork quantities and related equipment operation, fuel use, and emissions; and (3) eliminate the risk of poor trench backfill causing high- way settlement (Williammee, 2011). Trenchless technologies most often used are (Ward, 2018): • Cured in-place pipe (CIPP). Flexible, resin-impregnated fabric tube insert that is heat cured in-place inside the existing pipe. • Sliplining (SL). Inserting a new, smaller diameter pipe inside the old pipe. • Modified sliplining (MSL). Assembling a new pipe liner within the old pipe. • In-line replacement (ILR). Replacing an old pipe using pipe bursting or pipe removal methods. • Spray in-place pipe (SIPP). Spraying a cementitious or polymer coating on the inside of an existing pipe. • Close-fit pipe (CFP). Inserting a new deformed or folded pipe into an existing pipe and then expanding it to the old pipe size. Key References Williammee, R. S., Jr. 2011. Trenchless Technology for Drainage Structures. Texas DOT, Fort Worth, Texas. Ward, D. C. 2018. NCHRP Synthesis 519: The Renewal of Stormwater Systems Using Trenchless Technologies. Transportation Research Board of the National Academies, Washington, D.C.

Sustainable Construction Practices 77 9.10 Aesthetics Overview Aesthetics are a set of principles addressing the nature and appreciation of beauty. Aesthetics pro- duce measurable physical and psychological benefit in humans. Highway construction can influ- ence project aesthetics through (1) temporary construction facility aesthetics (e.g., fencing, offices, equipment) and (2) permanent infrastructure aesthetics affected by construction actions (e.g., contractor choices that affect bridge, wall, or other visual features). Aesthetic decisions outside the realm of construction (e.g., policies, community/design/architectural decisions) are not addressed. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity Project Requirement X Goodwill Motivations Sustainable Construction Practices • Economical aesthetic wall design. Achieve project aesthetic goals through economic and constructible wall design. • Context-sensitive rock slopes. Aesthetically pleasing rock slopes that provide stabilization and rockfall protection. • Construction site aesthetics. Temporary construction structures (e.g., fences, trailers, cranes) with aesthetic features. Principal Guidance, Assistance, and Tools Caltrans. 2016. Design Information Bulletin (DIB) 88: Wall Structure Aesthetic Guidelines. Caltrans, Sacramento, California (guidance on creating constructible wall aesthetics). Andrew, R. D., R. Bartingale, and H. Hume. 2011. Context Sensitive Rock Slope Design Solutions. FHWA-CFL/TD-11-002. Central Federal Lands Highway Division, Lakewood, Colorado. Bullard, D. L., N. M. Sheikh, R. O. Bligh, et al. 2006. NCHRP Report 554: Aesthetic Concrete Barrier Design. Transportation Research Board of the National Academies, Washington, D.C.

78 Sustainable Highway Construction Guidebook 9.10.1 Economical Aesthetic Wall Design Effort (time and cost): 2.3 Impact/Effort Ratio Human Welfare: 2.9 Environmental Benefit: 1.1 Cost Savings: 1.5 2.4 Summary Some owners and trade organizations provide guidance on how to create desirable aesthet- ics in an economical manner. Caltrans has an extensive guide on aesthetic wall treatments (Caltrans, 2016) that highlights design and contract features to implement for constructability and economy. Many owners specify a limited number of standard wall aesthetic patterns, but design-build projects allow the contractor latitude to select aesthetics within specified bounds. Aesthetics recommendations include (Caltrans, 2016): • To accommodate a gang form construction methodology, wall layout should be based on 4-foot or 8-foot dimensions. Expansion joints, weakened plane joints, begin and end curves, and wall footing step lengths should be placed on 8-foot increments. • When aesthetic treatments include vertical or horizontal patterns, wall footing step heights should match the pattern repeat dimensions to facilitate alignment of the pattern at adjacent panels. • Require elastomeric form liners because they provide for multiple uses and produce high- quality textures and patterns. • Repetitive patterns are preferred for ease of construction and cost savings, but non-repetitive patterns are acceptable to match existing corridor aesthetic treatments, comply with estab- lished corridor aesthetic guidelines, and satisfy stakeholder expectations. • Vertical patterns are preferred over horizontal patterns because construction can be more straightforward, resulting in cost savings. However, horizontal patterns are often required to achieve a context-appropriate aesthetic treatment. • Patterns and custom imagery for MSE walls must be compatible with the dimension of the modular face panel and the offset alternating pattern method of construction to assure proper alignment of patterns and images. • A referee sample for all wall aesthetic textures, patterns, and colors should be made available for review during the advertisement for bid, when available. Key References Caltrans. 2016. Design Information Bulletin (DIB) 88: Wall Structure Aesthetic Guidelines. Caltrans, Sacramento, California (guidance on creating constructible wall aesthetics). Schutt, J. R., K. L. Phillips, and H. C. Landphair. 2001. Guidelines for Aesthetic Design in Highway Corridors: Tools and Treatments for Texas Highways. FHWA/ TX-02/2113-3. Texas DOT, Austin, Texas (current practice in aesthetics design and guidelines for evaluating aesthetics). 9.10.2 Context-Sensitive Rock Slopes Effort (time and cost): 3.0 Impact/Effort Ratio Human Welfare: 2.2 Environmental Benefit: 1.8 Cost Savings: 1.1 1.7

Sustainable Construction Practices 79 Summary FHWA Federal Lands Highway Division has written about and extensively uses “context- sensitive rock slope design,” that is, rock slopes constructed such that they are consistent with the project’s surroundings, either natural, environmental, or relating to a historical setting or community. Existing excavation techniques for rock slopes often use blasting techniques originally designed for the mining industry, which tend to prioritize productivity and volume over aesthetics and environment (Andrew et al., 2011). Key References Andrew, R. D., R. Bartingale, and H. Hume. 2011. Context Sensitive Rock Slope Design Solutions. FHWA-CFL/TD-11-002. Lakewood, Colorado. 9.10.3 Construction Site Aesthetics Effort (time and cost): 2.0 Impact/Effort Ratio Human Welfare: 2.5 Environmental Benefit: 0.6 Cost Savings: 1.5 2.3 Summary Construction site aesthetics can be affected by colors and designs of temporary fencing, deco- rated cranes/derricks, and other designs on temporary structures or equipment. There is no general guidance for these types of aesthetics. They are usually left to owner policy, or contractor goodwill. Key References None.

80 Sustainable Highway Construction Guidebook 9.11 Walls Overview Highway walls are primarily used to manage changes in elevation, user/neighbor safety, and noise abatement. Choices between the many different types of walls possible (for example grav- ity, cantilever, mechanically stabilized earth, secant, sheet pile, gabion, soldier pile, and soil nail) are usually made based on context and cost. Highway construction sustainability considerations for walls concern environmental impacts (energy and emissions associated with a wall type and design) and human impacts (aesthetics, addressed in Section 9.10.1). There have been some life-cycle analyses of walls to determine the associated energy and emissions, but none that comprehensively compare energy and emissions across different wall types and/or earthwork berm options (if viable). Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity X Project Requirement X Goodwill Motivations Sustainable Construction Practices No viable SCPs were identified in this area. Principal Guidance, Assistance, and Tools Bobet, A. 2002. Guidelines for Use and Types of Retaining Devices. FHWA/IN/ JTRP-2001/28. Indiana DOT, Indianapolis, Indiana.

Sustainable Construction Practices 81 9.12 Bridges Overview Bridges in highway construction can range from large signature span multi-lane highway bridges to short single span roadway girder bridges to a variety of pedestrian and even wildlife bridges. This section addresses only the construction of highway bridges and the design as it relates to constructability. Bridge construction typically influences sustainability by building them quickly to reduce user delay, incorporating desired aesthetics, or using improved or alter- native materials and methods to reduce costs, lessen environmental impacts, and improve safety. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity X Project Requirement X Goodwill Motivations Sustainable Construction Practices • Accelerated bridge construction (ABC). Prefabricating bridges off-site or away from traffic to minimize traffic disruption, improve safety, and improve durability and quality. Specific ABC types are: slide-in bridge construction, self-propelled modular transporter construction, incremental launching method, and prefabricated bridge elements and systems. • Segmental concrete. Concrete bridges constructed in repetitive pieces that are progressively connected to form the complete bridge. • Geosynthetic reinforced soil-integrated bridge systems (GRS-IBS). Alternating layers of compacted granular fill material and geosynthetic reinforcement to provide support to small single span bridges. Principal Guidance, Assistance, and Tools Florida International University. n.d. Accelerated Bridge Construction University Transportation Center. Miami, Florida. https://abc-utc.fiu.edu. HNTB Corporation. 2013. Innovative Bridge Designs for Rapid Renewal: ABC Toolkit. SHRP 2 Report S2-R04-RR-2. Transportation Research Board of the National Academies, Washington, D.C. ASBI. 2008. Construction Practices Handbook for Concrete Segmental and Cable- Supported Bridges, 2nd Edition. American Segmental Bridge Institute, Buda, Texas.

82 Sustainable Highway Construction Guidebook 9.12.1 Accelerated Bridge Construction (ABC) Effort (time and cost): 3.5 Impact/Effort Ratio Human Welfare: 3.5 Environmental Benefit: 2.7 Cost Savings: 2.3 2.5 Summary ABC describes bridge construction methods focused on prefabricating as much of the bridge off-site or away from traffic as possible to (1) minimize traffic disruption, (2) improve worker and user safety, and (3) improve durability and quality (HNTB, 2013). Other benefits may be a reduced construction footprint in sensitive areas, lower cost, and faster construction. ABC methods either focus on (1) building replacement bridges nearby and then quickly moving the new bridge in and old bridge out, or (2) prefabricating bridge elements off-site and then quickly assembling them on site. ABC methods, especially custom one-off approaches, often have higher initial construction costs when compared to traditional methods. Design is moving toward more standardized, light, simple, and constructible design that lends itself to ABC at minimal cost (HNTB, 2013). There are several common ABC methods; the Utah DOT Structures Design and Detailing Manual (2017). has an excellent chapter on ABC that provides guidelines for selecting among these methods; many other DOTs have ABC guidance in their bridge design manuals. The University Transportation Center at Florida International University maintains an ABC project database for United States, available at https://abc-utc. fiu.edu/technology-transfer/project-research-databases. Slide-in bridge construction (also known as lateral slide). A replacement bridge is built on temporary supports, usually parallel to the existing bridge so as not to disrupt traffic. The road is then closed for a short period of time as the old bridge is slid out and the new bridge slid into place. The I-84 bridge over Dingle Ridge Road is a well-documented case study (Bhajandas et al., 2014) of this approach that includes construction techniques, construction costs/savings, user costs, lessons learned, and some scheduling information. Findings include an overall savings of $2.27 million or about 18% of what the project would have cost using a traditional construct in-place approach. Self-propelled modular transporter (SPMT). This works like the slide-in bridge construc- tion except that the new/replacement bridge is built in a staging area and moved into place with a large self-propelled modular transporter instead of slides. Utah DOT, a leader in this field, awarded its first self-propelled modular transporter project in 2007. Incremental Launching Method (also known as longitudinal launches). A bridge is assembled on one or both sides of its span, then pushed (launched) longitudinally into its final position in a series of increments. The incremental launching method can cost more than traditional methods but may be useful in avoiding work in an inaccessible or environ- mentally protected area below the bridge span. Other advantages include smaller equipment required for construction, better worker safety due to ground level assembly, and faster con- struction. Disadvantages are perceived risk, higher cost, and unfamiliarity with the method. (LaViolette et al., 2007). Prefabricated bridge elements and systems (PBES). Bridge components or systems that are fabricated off-site to reduce on-site construction time. PBES may consist of elements like precast concrete footings, abutments, girders, deck panels, and entire superstructures. FHWA has websites (https://www.fhwa.dot.gov/bridge/prefab) and publications describing methods of design to allow for PBES contracting and construction.

Sustainable Construction Practices 83 9.12.2 Segmental Concrete Key References HNTB Corporation. 2013. Innovative Bridge Designs for Rapid Renewal: ABC Toolkit. SHRP 2 Report S2-R04-RR-2. Transportation Research Board of the National Academies, Washington, D.C. Utah DOT. 2017. Structures Design and Detailing Manual. Salt Lake City, Utah. Bhajandas, A., J. Mallela, and S. Sadasivam. 2014. New York Demonstration Project: I-84 Bridge over Dingle Ridge Road Replacement using Superstructure Slide-In Technology. FHWA, Office of Infrastructure, Washington, D.C. LaViolette, M., T. Wipf, Y.-S. Lee, et al. 2007. Bridge Construction Practices using Incremental Launching. NCHRP Project 20-07/Task 229. Bridge Engineering Center. Center for Transportation Research and Education, Ames, Iowa. Culmo, M. 2011. Accelerated Bridge Construction—Experience in Design, Fabrication and Erection of Prefabricated Bridge Elements and Systems. FHWA-HIF-12-013. FHWA Highways for LIFE Program, Washington, D.C. Culmo, M., S. Sadasivam, and D. Gransberg. 2013. Contracting and Construction of ABC Projects with Prefabricated Bridge Elements and Systems. FHWA-HIF- 17-020. FHWA Highways for LIFE Program, Washington, D.C. FHWA. 2006. Prefabricated Bridge Elements & Systems (PBES) Cost Study: Accelerated Bridge Construction Success Stories. Washington, D.C. Effort (time and cost): 3.0 Impact/Effort Ratio Human Welfare: 1.7 Environmental Benefit: 1.9 Cost Savings: 2.3 2.0 Summary Concrete bridges constructed using repetitive elements that are progressively connected to form the complete bridge. Segmental concrete bridge construction can minimize work in restricted or environmentally protected areas below the bridge span and the repetitive construction techniques can be economical. Construction loading, as opposed to in-service loading, can often control aspects of design. Methods are typically span-by-span or balanced cantilever. Key References American Segmental Bridge Institute. 2008. Construction Practices Handbook for Concrete Segmental and Cable-Supported Bridges, 2nd Edition. Buda, Texas.

84 Sustainable Highway Construction Guidebook 9.12.3 Geosynthetic Reinforced Soil-Integrated Bridge Systems (GRS-IBS) Effort (time and cost): 2.6 Impact/Effort Ratio Human Welfare: 1.6 Environmental Benefit: 2.3 Cost Savings: 2.8 2.6 Summary Uses alternating layers of compacted granular fill material and geosynthetic reinforcement to provide support to small single-span bridges. The GRS-IBS abutments are easier to build and are 25 to 60 percent more cost-effective than conventional bridges. This method allows material recycling as the granular aggregate materials used in GRS courses can be reused at the end of the bridge abutments’ life cycle. It reduces the overall project cost by reducing the construction time, as many elements in common bridges are not needed, like deep foundations, bridge seat, bridge bearings, etc. It also ensures higher safety for workers as it eliminates the workers’ exposure to fumes and emissions due to piling activities. In addition, the system is easy to design and can be built in variable weather conditions. Key Reference Adams, M., J. Nicks, T. Stabile, et al. 2012. Geosynthetic Reinforced Soil Integrated Bridge System Interim Implementation Guide. FHWA-HRT-11-026. FHWA, Washington, D.C.

Sustainable Construction Practices 85 9.13 Pavement Overview Pavement, the durable surfacing of a roadway and its supporting structure, constitutes about 70% of annual state and local roadway expenditures in the United States (U.S. DOT, 2008) or at least $50 to $60 billion/year. Pavements, their construction, their condition during use, and their ultimate disposal can affect (1) energy consumption; (2) greenhouse gas emissions; (3) habitat loss, fragmentation, and change; (4) water quality; (5) the local hydrologic cycle; (6) air quality; (7) mobility; (8) access; (9) freight; (10) community; (11) depletion of non-renewable resources; and (12) economic development (Van Dam et al., 2015). This section is based on the FHWA’s Towards Sustainable Pavement Systems: A Reference Document (Van Dam et al., 2015) and specifically focuses on Chapter 5 (Construction Con- siderations to Improve Pavement Sustainability). Other sustainability ideas contained in the FHWA document are outside the construction scope of this guidebook. Table 4 shows how sustainability ideas from Chapter 5 of the FHWA reference document are addressed in this guidebook. Most of these sustainability ideas are addressed elsewhere in this guidebook. This section is largely a review of construction quality issues, which tend to affect pavement durability and long-term performance. Sustainability Idea Examples Where Addressed in this Guidebook Fuel consumption and emissions Minimize haul distances Construction efficiency Not addressed. Efficiency and method choices depend on context and are best evaluated by each project and/or contractor. Materials use On-site recycling Alternate materials Section 9.15 Materials Noise Construction time restrictions Equipment noise Section 9.20 Construction Noise Accelerated construction Traffic control strategies Project management/control Section 9.5 Scheduling Erosion, water runoff, and sedimentation NPDES requirements Not addressed. NPDES is a regulatory requirement. Construction quality Asphalt pavement density Prevent segregation Longitudinal joints Smoothness Dowel bar alignment Surface friction and noise This Section Water resources Concrete wash water use This section Contracting alternatives Multi-parameter bidding Section 0 Contracting Incentives Equipment operation Reduce idling Use alternative fuels Equipment emissions reduction Section 0 Equipment Table 4. Sustainability Ideas from the FHWA’s Towards Sustainable Pavement Systems: A Reference Document and Where They Are Addressed in This Guidebook

86 Sustainable Highway Construction Guidebook Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity X Project Requirement X Goodwill Motivations Sustainable Construction Practices • General pavement – Smoothness specification. Specify pavement smoothness because smoother pavements can result in reduced vehicle operating costs and emissions, and may be more durable. – Pavement warranties. Use warranties to reduce future risk and incentivize quality construction. – On-site recycling/reuse. Paving methods that recycle/reuse existing pavement materials on site. • Asphalt pavement – Density. Improve density to increase pavement life, and/or streamline methods for mea- suring density in the field. – Longitudinal joints. Improve longitudinal joint compaction to reduce the risk of early pavement failure on longitudinal joints. – Eliminate segregation. Eliminate the separation of coarse and fine aggregate in the paving process as this can lead to early pavement failure. – Eliminate density differentials. Eliminate isolated cool spots in the paved mat that may be inadequately compacted and lead to early failure. – Tack coat application. Methods to ensure the proper amount of tack coat is applied on existing surfaces (and on surfaces between pavement layers) to ensure proper bonding. • Concrete pavement – Dowel alignment. Measure and specify dowel bar alignment to reduce the risk of early pavement failure from misaligned dowels. – Use HIPERPAV to predict early age pavement behavior. Predict early age concrete pave- ment behavior to reduce the risk of early construction-related failure. – Non-potable water for concrete mixtures and wash water. Use non-potable water to reduce costs and conserve treated, potable water. Principal Guidance, Assistance, and Tools Van Dam, T. J., J. T. Harvey, S. T. Muench, et al. 2015. Towards Sustainable Pavement Systems: A Reference Document. FHWA-HIF-15-002. FHWA. Washington, D.C.

Sustainable Construction Practices 87 9.13.1 Smoothness Specification Effort (time and cost): 2.1 Impact/Effort Ratio Human Welfare: 2.4 Environmental Benefit: 2.1 Cost Savings: 1.4 2.9 Summary Smoothness is a defining quality characteristic for pavement. Smoother pavements are gener- ally thought to be an indicator of higher construction quality. They reduce vehicle operating costs and emissions, and there is evidence that they are more durable. Tactics for achieving smoothness vary with pavement type, but include underlying surface preparation, uniform delivery of material through the paver, grade control, compaction/consolidation efforts, and joint construction. About ¾ of state DOT asphalt pavement specifications have International Roughness Index– based smoothness requirements and about 90% of those involve incentive/disincentive pay adjust- ments based on statistical analysis (Merritt et al., 2015). About half of smoothness is related to the roughness of the underlying layer and improvements in smoothness per lift are on the order of 40% to 65% at most. For those states that base pay on smoothness, the lower limit for full pay (lower values would result in a penalty) ranges from 43 to 100 inches/mile (Merritt et al., 2015). Incentive/disincentive specifications for smoothness should also allow for construction methods to improve smoothness such as leveling course and milling of the existing surface. Key References Merritt, D. K., G. K. Chang, and J. L. Rutledge. 2015. Best Practices for Achieving and Measuring Pavement Smoothness, A Synthesis of State-of-Practice. Southeast Transportation Consortium, Final Report 550. Louisiana Transportation Research Center, Baton Rouge, Louisiana. Brock, J. D., and J. Hedderich. 2007. Pavement Smoothness. Technical Paper T-123. Astec Industries, Chattanooga, Tennessee. 9.13.2 Pavement Warranties Effort (time and cost): 2.4 Impact/Effort Ratio Human Welfare: 1.2 Environmental Benefit: 1.3 Cost Savings: 1.5 1.7 Summary Some U.S. and international owners use pavement warranties. Stated reasons for their use are improved quality and reduced owner oversight during construction. Essentially, a warranty is an added up-front expense (warranties are priced and bid accordingly) to hedge against the risk of a costly expense later. NCHRP Report 699 (Scott et al., 2011) classifies warranties as: • Type 1 (materials and workmanship). Less than 3 years. Meant to reduce the risk of cata- strophic failure due to poor construction.

88 Sustainable Highway Construction Guidebook 9.13.3 On-Site Recycling/Reuse Key Reference Scott, S., T. Ferragut, M. Syrnick, and S, Anderson. 2011. NCHRP Report 699: Guidelines for the Use of Pavement Warranties on Highway Construction Projects. Transportation Research Board of the National Academies, Washington, D.C. • Type 2 (short-term performance). 5 to 10 years. Meant to shift some of the responsibility to the contractor such as mix or structural design. • Type 3 (long-term performance). 20 or more years. Meant to shift responsibility for a pave- ment’s long-term performance to the contractor. Effort (time and cost): 2.3 Impact/Effort Ratio Human Welfare: 1.8 Environmental Benefit: 3.9 Cost Savings: 3.0 3.8 Summary A variety of paving methods have been developed to reuse or recycle in-place existing pave- ments. Sustainability benefits are generally reduced material costs, reduced transportation needs, and, in some cases, reduced construction time or cost, especially when comparing on- site recycling/reuse to a complete pavement reconstruction effort. These methods should not be used in lieu of proper maintenance and rehabilitation timing and techniques, which is generally less costly in the long term. These methods are: • Crack-and-seat. Existing deteriorated concrete pavement is cracked into smaller slabs, then overlaid with asphalt pavement. The smaller slabs are less likely to cause reflective cracking in the asphalt pavement overlay. This method is most successful with thicker (greater than 7 inches) asphalt pavement overlays (SHRP 2 R23, 2013). While it is most common to crack- and-seat unreinforced concrete pavement, it can be adapted to reinforced concrete pavement by first sawing the pavement in the transverse direction every 4 to 5 ft., deep enough to cut the reinforcing steel. • Rubblization. Existing deteriorated concrete pavement is turned into rubble by a fracturing process, then overlaid with asphalt or concrete pavement. The rubble is left in place and functions as a high-quality base for the asphalt pavement overlay. Rubblization works best when the existing subgrade provides adequate strength, support, and drainage. If viable, crack-and-seat is usually preferred to rubblization since it retains more of the existing pave- ment stiffness. • Full-depth reclamation (FDR). The existing full pavement thickness and some portion of the underlying material are pulverized, blended, and stabilized (with cement, lime, foamed/ emulsified asphalt, etc.) to provide a high-quality base material upon which to pave. FDR is generally considered if the existing pavement is too distressed to benefit from a traditional overlay. In the right situations FDR can be up to about 50% less expensive than a full pave- ment reconstruction. • Cold in-place recycling (CIR). Some fraction of the existing pavement thickness (up to about 4 inches) is milled up, crushed, and screened, then mixed with asphalt cement (or emulsified/ foamed asphalt) and replaced to serve as a high-quality base material upon which to pave.

Sustainable Construction Practices 89 CIR material must cure in place in good weather for several days to 2 weeks (depending upon materials and weather conditions) before it can be overlaid (Dunn and Cross, 2015). CIR is generally considered if the existing pavement is too distressed to benefit from a traditional overlay but has enough thickness for CIR. • Hot in-place recycling (HIR). The existing asphalt pavement surface (usually 3/4 to 2 inches deep) is heated and softened, scarified or milled, supplemented with aggregate and/or addi- tives (if required), mixed, and then replaced. HIR is generally considered if the existing pave- ment has only shallow (to 2 inches or less) distresses that can be scarified/milled out by the process. • On-site recycling. Existing asphalt or concrete pavement is crushed on site using mobile crushers. The recycled pavement is sized, placed on grade, and compacted to provide a sub- base or base for a new asphalt or concrete pavement. Key References SHRP 2 R23. 2013. Recommendations for the Design and Construction of Long Life Flexible Pavement Alternatives Using Existing Pavements. http://www. pavementrenewal.org/#resources. Dunn, L., and S. Cross. 2015. Basic Asphalt Recycling Manual, 2nd edition. Asphalt Recycling and Reclaiming Association, Annapolis, Maryland. 9.13.4 Density Effort (time and cost): 1.9 Impact/Effort Ratio Human Welfare: 1.1 Environmental Benefit: 1.7 Cost Savings: 2.4 2.8 Summary Experimental evidence over the past 50 years shows that, within a reasonable range, higher in-place asphalt pavement density results in better pavement performance and longer pavement life (Tran et al., 2016). Over time, this has led to better compaction equipment, asphalt pave- ment density standards, use of a variety of compaction aids, and nominal maximum aggregate size (NMAS) versus lift thickness standards. Density can be considered the best single indicator of asphalt pavement construction quality. Key asphalt pavement density sustainable practices follow: • Higher in-place density standards. An ongoing (as of 2018) FHWA demonstration project (Aschenbrenner et al., 2017) examines the impact of higher density on asphalt pavement durability. Literature survey of the project shows that in laboratory testing, higher densi- ties (93% to 94% Rice density compared with typical specification values of 91% to 92% Rice density) generally result in improved fatigue life and less rutting. Field demonstra- tions in 10 states generally show that densities in the 93% to 95% range are possible using a combination of methods including more rollers/passes, higher asphalt content, lower mix design gyrations, better paving/compaction consistency, and by following long-established construction best practices.

90 Sustainable Highway Construction Guidebook • Intelligent compaction. Intelligent compaction (IC) is a way to monitor compaction effort in near real time. IC uses accelerometers on rollers to measure compaction effort and material response to estimate asphalt pavement density. GPS is typically used to locate data and inte- grated systems can show maps of estimated density in near real time. While the reliability and accuracy of IC density estimates still needs improvement, the GPS output that shows roller location and roller passes can be useful. • Non-nuclear field density measurement. The standard for measuring in-place density is the field core tested in the laboratory. For quicker density results the nuclear gauge has been used since the 1970s. While a properly calibrated nuclear gauge is able to give density read- ings within minutes, its radioactive source requires licensing, a radiation safety program, gauge safety certification training, gauge security/control, calibration, and proper disposal procedures. Gauges without nuclear sources (or sources small enough to be exempt from controls), usually electromagnetic gauges, can be quicker to use and are subject to fewer rules. Results from many comparative studies [most of them done in the 2001 to 2008 time frame for the Pavement Quality Indicator and PaveTracker, and then again in the 2010 to 2015 time frame for ground penetrating radar (GPR)] are mixed. Most of the best-performed studies show that electromagnetic gauge accuracy is highly dependent on calibrated dielec- tric values and the presence of water (Sargand et al., 2005). Under good conditions, daily calibrations done correctly can produce correlations with cores on par with nuclear gauges. Predominantly, non-nuclear gauges are recommended for contractor quality control but not for acceptance testing. • Variable density standards based on NMAS. Most pavements are designed to be imperme- able, which is vital to their durability and life expectancy. There is a relationship between NMAS, density, and permeability (Brown et al., 2004): as NMAS increases, the density required to achieve an impermeable asphalt pavement increases. For instance, ⅜- and ½-inch NMAS mixtures may become permeable below about 92% to 93% of theoretical maximum density (TMD), while ¾-inch NMAS mixtures become permeable below approximately 94.5% of TMD. If an impermeable asphalt pavement is wanted (and it usually is), the required density to achieve this should vary with NMAS. • Lift thickness ê 4 ë NMAS. NCHRP Report 531 (Brown et al., 2004) recommends the mini- mum paving depth be at least 3 × NMAS for fine graded mixes and 4 × NMAS for coarse graded and SMA mixes. This allows enough room for aggregate to rearrange in the mixture from the weight and vibration of the paver screed and rollers. Thinner lifts cool more rapidly (for instance, a 2-inch lift cools twice as fast as a 2.5-inch lift). At mat thicknesses less than about 1.5 × NMAS, the paver screed may be supported by large aggregates in the mixture rather than floating on the mixture as a whole, which can effectively prevent compaction. • Warm mix asphalt as a compaction aid. A variety of warm mix asphalt (WMA) additives and processes have been found to aid compaction at normal construction temperatures. In some instances, WMA additives have been specified as compaction aids for particularly stiff mixes. For example, high PG 82 grades, asphalt rubber mixtures, open-graded mixtures requiring hand work (Prowell, 2012). Key References Tran, N., P. Turner, and J. Shambley. 2016. Enhanced Compaction to Improve Durability and Extend Pavement Service Life: A Literature Review. NCAT Report 16-02R. National Center for Asphalt Technology, Auburn, Alabama.

Sustainable Construction Practices 91 9.13.5 Longitudinal Joints Aschenbrener, T., E. R. Brown, N. Tran, and P. B. Blankenship. 2017. Demonstration Project for Enhanced Durability of Asphalt Pavements through Increased In-Place Pavement Density. NCAT Report 17-05. National Center for Asphalt Technology, Auburn, Alabama. FHWA. 2018. Intelligent Compaction. https://www.fhwa.dot.gov/pavement/ic. Sargand, S. M., S.-S. Kim, and S. P. Farrington. 2005. A Working Review of Available Non-Nuclear Equipment for Determining In-Place Density of Asphalt. FHWA/OH-2005/18. Ohio Research Institute for Transportation and the Environment, Ohio University, Athens, Ohio. Brown, E. R., M. R. Hainin, A. Cooley, and G. Hurley. 2004. NCHRP Report 531: Relationship of Air Voids, Lift Thickness, and Permeability in Hot Mix Asphalt Pavements. Transportation Research Board of the National Academies, Washington, D.C. Prowell, B. D. 2012. Warm-Mix Asphalt: Best Practices 3rd Edition. QIP-125. National Asphalt Pavement Association, Lanham, Maryland. Kristjánsdóttir, O. 2000. Warm Mix Asphalt for Cold Weather Paving. WA-RD 650.1. Washington State DOT, Olympia, Washington. Effort (time and cost): 1.9 Impact/Effort Ratio Human Welfare: 1.2 Environmental Benefit: 1.4 Cost Savings: 1.9 2.4 Summary Low compaction and surface irregularities are more prevalent in longitudinal joints and lead to premature cracking and raveling. Ideally, the joint between two construction passes of HMA should be an integral part of the pavement structure and as durable as the rest of the finished mat. There are several commonly accepted longitudinal joint construction best prac- tices including proper joint overlap, rolling from the hot side 6 inches away from the joint, and using rubberized joint material and notched wedge joints (Kandhal, 2002). Other useful techniques are cutting back the cold edge (often done in airfield work) and echelon paving to create a hot joint. Key Reference Kandhal, P. S. 2002. Evaluation of Eight Longitudinal Joint Construction Techniques for Asphalt Pavements in Pennsylvania. NCAT Report 02-03. National Center for Asphalt Technology, Auburn, Alabama.

92 Sustainable Highway Construction Guidebook 9.13.6 Eliminate Segregation Effort (time and cost): 2.0 Impact/Effort Ratio Human Welfare: 1.3 Environmental Benefit: 1.6 Cost Savings: 1.7 2.3 Effort (time and cost): 1.9 Impact/Effort Ratio Human Welfare: 1.0 Environmental Benefit: 1.2 Cost Savings: 2.0 2.2 Summary Segregation is a separation of coarse and fine aggregate particles during the production and paving process. The result is a non-uniform mat that, in places, does not conform to the original job mix formula and performs poorly. Eliminating segregation requires effort throughout pro- duction and laydown including stockpiling, hot plant operations, truck loading, material trans- fer vehicle use, and paver operation (Brock et al., 2003). Key Reference Brock, J. D., and G. Renegar. 2003. Segregation: Causes and Cures. Technical Paper T-117. Astec Industries, Chattanooga, Tennessee. 9.13.7 Eliminate Density Differentials Summary Construction-related temperature differentials (sometimes called “thermal segregation”) are isolated cooler areas of the mat that may not be adequately compacted using a rolling pattern designed for the majority mat temperature. Thus, they can result in isolated areas of low density that fail prematurely by raveling and cracking. Often, these areas are caused by the top surface of the mix in the dump truck being cooled during transit and then passing through the paver and being placed in mat relatively in-tact. Infrared cameras and paver-mounted equipment can be used to detect areas of low temperature as they are paved. The resulting isolated areas of low density in the mat may not be detected by normal random sampling, so some state DOTs use an additional specification to address them. Specifications usually require a “thermal profile” (temperature measurements taken along a short distance of 100 to 500 ft.). Areas significantly cooler than the surrounding mat require further investigation with density testing. Corrective action and/or penalties may result. Key References Washington State DOT. 2017. SOP 733: Determination of Pavement Density Differentials Using the Nuclear Density Gauge. Materials Manual M40-01.27. Olympia, Washington. Texas DOT. 2015. Test Procedure for Thermal Profile of Hot Mix Asphalt. Texas DOT Designation: Tex-244-F.

Sustainable Construction Practices 93 9.13.8 Tack Coat Application Effort (time and cost): 1.6 Impact/Effort Ratio Human Welfare: 0.9 Environmental Benefit: 1.6 Cost Savings: 2.1 3.0 Summary Tack coat is the application of an asphalt material to an existing pavement surface intended to aid in bonding a new pavement surface to the existing surface. Pavement design assumes all asphalt pavement layers are adequately bonded. If not, the resulting de-bonded pavement layers are, each by themselves, too weak to withstand traffic loading and may suffer slippage and fatigue cracking. Tack coat represents a small job expense (usually less than 0.5% of the bid price) but incorrect application and potential de-bonding failure is an extreme consequence. Several prac- tices can improve tack coat application: • Pay for tack coat separately. Tack coat can be paid for as a separate item or included as inci- dental to the bid price of the asphalt material. Tack coat as a separate pay item is done by 66% of U.S. DOTs as of 2017 (Gierhart, 2017). Paying for tack as a separate item best aligns the goals of owner and contractor—the owner can request more tack coat and the contractor can provide it and be properly compensated for the additional material. • Control tack coat dilution. Often, slow setting tack coats are diluted with water to help the tack truck apply the tack coat more evenly. However, dilution must be closely controlled because an inaccurately determined dilution rate will result in an incorrect residual asphalt application. As of 2017, 48% (24/50) of state DOTs allow dilution (Gierhart, 2017). If dilution is allowed, only do so at the asphalt supplier’s terminal as it is better controlled. It is best to verify the dilution rate before applying the tack coat so that a proper residual asphalt rate will result. Or, it may be easiest to not allow dilution and eliminate this issue. • Use trackless tack coat. A common issue with tack coat is that construction machines that drive on it pick it up with their rubber tires and remove it from the existing pavement surface, which can reduce bond strength in the wheelpaths. Since the mid-2000s, trackless tack coat has been available from some manufacturers (for example, NTSS-1HM). Not all owners allow trackless tack, but when properly applied it appears to largely prevent tracking. Key References Gierhart, D., and D. R. Johnson. 2017. NCHRP Synthesis 516: Tack Coat Specifications, Materials, and Construction Practices. Transportation Research Board of the National Academies, Washington, D.C. Mohammad, L., M. A. Elseifi, A. Bae, and N. Patel. 2012. NCHRP Report 712: Optimization of Tack Coat for HMA Placement. Transportation Research Board of the National Academies, Washington, D.C. 9.13.9 Dowel Alignment Effort (time and cost): 1.3 Impact/Effort Ratio Human Welfare: 0.8 Environmental Benefit: 1.3 Cost Savings: 1.6 2.9

94 Sustainable Highway Construction Guidebook Summary In jointed concrete pavement, dowel bars are typically used to provide load transfer across trans- verse joints. Ideally, dowel bars should be aligned parallel to the surface and centerline of the con- crete slab and centered on the joint. Significant deviations from this may cause pavement distress but dowel alignments measured in the field are, in general, not severe enough to affect long-term pavement performance. Use of non-destructive magnetic tomography measurement devices, like MIT Scan-2, can provide accurate dowel bar location information once they are imbedded in the pavement. Many DOTs have dowel bar alignment specifications but only some require alignment testing. Testing, often done with the MIT Scan-2 device, is used to measure dowel bar alignment either for every transverse joint in a short test section or for a randomly selected set of joints. Key References Khazanovich, L., and M. Snyder. 2009. NCHRP Report 637: Guidelines for Dowel Alignment in Concrete Pavements. Transportation Research Board of the National Academies, Washington, D.C. Colorado DOT. (2017). Standard Specifications for Road and Bridge Construction. Colorado DOT, Denver, Colorado. 9.13.10 Use HIPERPAV to Predict Early Age Pavement Behavior Effort (time and cost): 2.0 Impact/Effort Ratio Human Welfare: 0.9 Environmental Benefit: 1.3 Cost Savings: 1.8 2.0 Summary HIPERPAV is a free Windows-based program developed to assess early age (first 72 hours) behavior of concrete pavement. Using basic design and construction information, HIPERPAV can predict strength and stress development in concrete pavement over its first 72 hours. This can identify situations (for example, an extremely hot environment) that may lead to early age cracking and failure, and help analyze preventive measures too. Key Reference The Transtec Group. 2009. HIPERPAV. http://www.hiperpav.com. 9.13.11 Non-Potable Water for Concrete Mixtures and Wash Water Effort (time and cost): 1.5 Impact/Effort Ratio Human Welfare: 1.8 Environmental Benefit: 3.2 Cost Savings: 1.7 4.6

Sustainable Construction Practices 95 Summary Potable water is allowed as concrete mixing water without testing. However, ASTM C1602/ C1602M (Standard Specification for Mixing Water Used in the Production of Hydraulic Cement Concrete) allows non-potable water in any proportion so long as it produces similar compres- sive strength (at least 90% of 7-day compressive strength) and set time (up to 1 hour earlier to 1.5 hours later). Optional limits on chloride, sulfate, alkaline and total solids may also be included. Water from concrete production operations (for example, wash water) may be subject to more tests. In some situations, additional testing requirements may be justified in order to use a convenient, free, or environmentally responsible source of water (for example, lake water, collected stormwater in a concrete mixing plant, or treated wastewater). Non-potable water can also be used for other purposes such as concrete wash water. Key References Portland Cement Association. 2016. Design and Control of Concrete Mixtures, 16th edition. Skokie, Illinois. University of Miami, Politecnico di Milano, and Buzzi Unicem, eds. 2018. SEACON: Sustainable concrete using seawater, salt-contaminated aggregates, and non- corrosive reinforcement. Deliverable D7.3, Final Report.

96 Sustainable Highway Construction Guidebook 9.14 Work Zone Traffic Control Overview Work zone traffic control refers to the temporary procedure enacted in a work zone to ensure continuity of movement of motor vehicles, bicycles, and pedestrians. It also accounts for the safety of workers and drivers, as well as accommodates efficient construction and resolution of traffic incidents. The Manual on Uniform Traffic Control Devices (23 CFR 655, Subpart F). states that temporary traffic control is needed any time the normal function of a roadway is suspended. Effective work zone traffic control can reduce crashes; improve worker, driver, and pedestrian safety; and reduce congestion, which reduces fuel use and emissions. Sustainability approaches to work zone traffic control usually involve improving traffic operations within the work zone and better informing users and workers. Many resources provide guidance spe- cifically on intelligent transportation system solutions used in work zone traffic control (for example, use of technology to collect and communicate traffic information). Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity Project Requirement X Goodwill Motivations Sustainable Construction Practices • Merge control. Methods to control vehicle merging behavior to improve mobility and driver/ worker safety. • Speed management. Manage speed through work zones to improve driver/worker safety and improve traffic mobility through the work zone. • Driver information systems. Systems designed to provide information to manage driver expectations and assist in detour route choice. • Oversized load detection. Technology to detect and warn oversized vehicles before they enter a work zone. • Construction vehicle entering/exiting. Technology to detect when trucks are entering/ exiting the work zone and warn drivers. Principal Guidance, Assistance, and Tools American Traffic Safety Services Association. 2008. ITS Safety and Mobility Solutions: Improving Travel through America’s Work Zones. Fredericksburg, Virginia.

Sustainable Construction Practices 97 Key References Datta, T., K. Schattler, P. Kar, and A. Guha. 2004. Development and Evaluation of an Advanced Dynamic Lane Merge Traffic Control System for 3 to 2 Lane Transition Areas in Work Zones. Michigan DOT, Lansing, Michigan. FHWA. 2017. Intelligent Transportation Systems (ITS) & Technology. Work Zone Management Program. https://ops.fhwa.dot.gov/wz/its/index.htm. Ullman, G., J. Schroeder, and D. Gopalakrishna. 2014. Use of Technology and Data for Effective Work Zone Management: Work Zone ITS Implementation Guide. FHWA-HOP-14-008. FHWA, Washington, D.C. Work Zone Intelligent Transportation System Implementation Tool, v1.0 (downloadable software that is a companion to Ullman et al., 2014 and is intended to be used by agencies in selection, design, procurement, deployment and evaluation of ITS systems for work zone use). Luttrell, T., M. Robinson, J. Rephlo, et al. 2008. Comparative Analysis Report: The Benefits of Using Intelligent Transportation Systems in Work Zones. FHWA-HOP-09-002. FHWA, Washington, D.C. 9.14.1 Merge Control Effort (time and cost): 1.9 Impact/Effort Ratio Human Welfare: 3.1 Environmental Benefit: 0.7 Cost Savings: 1.2 2.6 Summary Highway construction operations often require closing one or more lanes of traffic, which results in decreased roadway capacity, lane merging, user delay/costs, and increased safety risks for workers and users. Controlling vehicles and their behavior in work zone lanes has been well researched and a variety of methods have been identified that can be broadly categorized as: • Early control. Strategies to warn users in advance of lane closures. Ideal when demand is less than capacity. Michigan DOT reports that a system creating an enforceable early no-passing zone had a 1.96:1 benefit-to-cost ratio in the situation analyzed (Datta et al., 2004). • Late merge control. Strategies to makes use of the full capacity of the roadway up to the required merge. Ideal when the roadway is at or near capacity. Beacher et al. (2004) found that late merge was especially advantageous when the fraction of trucks was high (greater than 20%). • Signalized merge control. Controls a merge using a signal that alternately allows cars from each lane into the reduced lane section. Ideal when demand exceeds capacity, but not recom- mended below 1,800 veh/hr/lane (Kurker et al., 2014).

98 Sustainable Highway Construction Guidebook Beacher, A. G., M. D. Fontaine, and N. J. Garber. 2004. Evaluation of the Late Merge Work Zone Traffic Control Strategy. Virginia Transportation Research Council, Charlottesville, Virginia. Kurker, M. et al. 2014. Minimizing User Delay and Crash Potential through Highway Work Zone Planning. Texas DOT and Center for Transportation Research of University of Texas, Austin, Texas. 9.14.2 Speed Management Effort (time and cost): 1.9 Impact/Effort Ratio Human Welfare: 2.9 Environmental Benefit: 1.0 Cost Savings: 1.2 2.7 Summary Manage speed through work zones to improve driver and worker safety and improve traffic mobility through the work zone. Techniques focus on reducing speeds in the work zone, avoiding sudden braking, and enforcing existing work zone traffic rules. In general, some techniques lose their effectiveness once drivers become accustomed to them and many methods are attempts to supplement enforcement, which is limited by budget and staffing (Shaw et al., 2015). • Speed management. Strategies to manage and enforce speed limits within work zones. According to NCHRP Synthesis 482, effective methods are: enforcement, temporary trans- verse rumble strips, and electronic speed feedback systems. Other, less used effective methods are: pilot/pace vehicles, chicanes (Iowa weave), and lane width reductions. • Enforcement. NCHRP Report 746 provides guidance for traffic enforcement planning, opera- tions, and administration for high-speed (> 45 mph) work zones. • Changeable speed limits. Systems that allow setting and displaying temporary work zone speed limits that can be increased back to normal speed when work zone activity stops. • Stopped or slow traffic warning. Queue detection tools monitor vehicle speed and report to drivers through a changeable message sign or other warning systems. Key References Shaw, J. W., M. V. Chitturi, W. Bremer, and D. A. Noyce. 2015. NCHRP Synthesis 482: Work Zone Speed Management. Transportation Research Board of the National Academies, Washington, D.C. FHWA. 2017. Work Zone Speed Management. Work Zone Management Program. https://ops.fhwa.dot.gov/wz/traffic_mgmt/wzsm.htm. Ullman, G. L., M. A. Brewer, J. E. Bryden, et al. 2013. NCHRP Report 746: Traffic Enforcement Strategies for Work Zones. Transportation Research Board of the National Academies, Washington, D.C.

Sustainable Construction Practices 99 9.14.3 Driver Information Systems Effort (time and cost): 2.3 Impact/Effort Ratio Human Welfare: 3.4 Environmental Benefit: 0.9 Cost Savings: 1.1 2.4 Effort (time and cost): 1.6 Impact/Effort Ratio Human Welfare: 1.9 Environmental Benefit: 0.5 Cost Savings: 1.3 2.3 Summary Systems designed to provide information to manage driver expectations and assist in detour route choice. Travel time information helps users make decisions and relieves frus- tration. One project in Arizona (FHWA, 2004) used measured travel times as a basis for contractor incentives/disincentives. The $42 million, 13.5-mile 2-lane rural highway project provided a $400,000 bonus fund from which money was deducted for excess travel time through the work zone. The contractor earned 96% of the bonus fund. With similar tech- nology, a project can measure travel times and just provide that information to users in the form of estimated travel time or delay time. Travel time estimation tends to be biased toward slower speeds since slower moving lanes provide more data, so typical estimations must be corrected for this (Suh et al., 2016). Key References American Traffic Safety Services Association. 2008. ITS Safety and Mobility Solutions: Improving Travel through America’s Work Zones. Fredericksburg, Virginia. Suh, W. et al. 2016. Work Zone Technology Testbed. Georgia Transportation Institute for Georgia DOT, Forest Park, Georgia. FHWA. 2004. Intelligent Transportation Systems in Work Zones: A Case Study: Work Zone Travel Time System. Reducing Congestion with the Use of a Traffic Management Contract Incentive during the Reconstruction of Arizona State Route 68. FHWA-HOP-04-032. Washington, D.C. 9.14.4 Oversized Load Detection Summary Tall or wide loads may have difficulty making it through work zones and can cause damage and major delays. Work zones that temporarily reduce bridge clearances or significantly reduce lane widths can use portable message signs or warning lights to warn drivers when especially tall or wide vehicles are detected. While not routinely reported, not all drivers heed these warnings, and lane/road closures should be considered a less risky alternative.

100 Sustainable Highway Construction Guidebook 9.14.5 Construction Vehicle Entering/Exiting Key Reference American Traffic Safety Services Association. 2008. ITS Safety and Mobility Solutions: Improving Travel through America’s Work Zones. Fredericksburg, Virginia. Effort (time and cost): 1.8 Impact/Effort Ratio Human Welfare: 2.2 Environmental Benefit: 0.6 Cost Savings: 1.4 2.3 Summary Construction vehicles entering the work zone from the traffic stream can cause disruption and driver confusion; especially at night. Portable message signs can be used to indicate when trucks enter or exit the work zone to warn drivers. Key Reference American Traffic Safety Services Association. 2008. ITS Safety and Mobility Solutions: Improving Travel through America’s Work Zones. Fredericksburg, Virginia.

Sustainable Construction Practices 101 9.15 Materials Overview A multitude of materials are used in highway construction, but aggregate, asphalt cement, portland cement, and steel make up the majority by weight and volume. Materials extrac- tion and production can be resource intensive and is usually the highest contributor (by a good margin) to a project’s initial construction cost and environmental footprint (for example, GHG emissions and energy use). Therefore, materials continue to be a primary focus of sustainable highway construction (and other construction). Materials sustainability goals are: • Reduce the amount of virgin materials used. Materials extraction can be energy/emissions intensive and sources for new virgin materials are more difficult to find and get permitted. • Reduce the impact of materials extraction and production. Acknowledging that virgin mate- rials are still needed, it is appropriate, when possible, to reduce the human, environmental, and cost impacts of their extraction and production. • Reduce the impact of materials transportation. Most highway construction materials must be transported to the project site. Since most highway construction materials are heavy and relatively cheap on a volume or weight basis, transportation is a major materials cost and contributor to environmental impacts. • Extend the life of infrastructure products. The more durable and longer-lasting infrastruc- ture is, the less material is needed to maintain it and/or renew it over time. When proposing a materials solution as sustainable, it should address one or more of these goals. These goals are achieved by the following general methods: • Reduce, reuse, and recycle highway materials. This reduces the amount of virgin materials needed and can reduce transportation costs. Emphasize in-situ reuse and recycling when possible. • Use recycled co-products and waste materials (RCWMs) from other industries. When using RCWM, consider their impact on structural and durability behavior. Some of these materials can improve highway infrastructure performance (for example, ground tires as crumb rubber in asphalt cement, coal production fly ash, and steel production slag in con- crete) and are currently used in highways. In addition, consider minimizing the haul dis- tances the RCWM gets transported. Finally, ensure that the inclusion of RCWM does not make the material difficult to recycle in future. • Improve the materials production process. Production improvement can reduce cost, envi- ronmental burden, and improve human welfare (for instance, more efficient heating or the use of warm mix asphalt additives). • Use alternate materials. Identify alternate materials (with a different production process) that may be less expensive or result in lower human and environmental impacts (for instance, bio-binders as asphalt replacement, light weight aggregate). • Use local materials. The closer the materials are to the construction site, the lower their transportation impacts. A more intensive treatment of pavement materials is available in Chapter 3 of FHWA’s Towards Sustainable Pavement Systems: A Reference Document (2015), available from FHWA’s Sustainable Pavements Program (https://www.fhwa.dot.gov/pavement/sustainability).

102 Sustainable Highway Construction Guidebook Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity X Project Requirement X Goodwill Motivations Sustainable Construction Practices • Reduce materials use. Design structures and features can be altered to produce equal or better function but with less materials use. • Reuse existing materials in place. Keep existing infrastructure or portions of it in place rather than remove-and-replace. • Recycle highway materials. Recycle existing highway materials such as asphalt and concrete pavement. • Use co-products and waste materials from other industries. Use materials such as ground tire rubber, fly ash, and slag to improve highway materials. • Use alternate or improved materials. Use alternate or improved materials that are equal or better in performance but can reduce cost, environmental burden, and risk of failure. • Local materials. Use materials closer to the project to reduce transportation impacts. • Environmental product declarations (EPDs). EPDs are third-party verified cradle- to-gate life-cycle assessment based environmental impact declarations that reliably communicate potential environmental impacts from a material being used in construc- tion. The impacts can be used to benchmark impacts of a pavement or construction pro- cess and, in the long-run, to consider improvements in design and construction to reduce impacts. Principal Guidance, Assistance, and Tools Van Dam, T. J., J. T. Harvey, S. T. Muench, et al. 2015. Towards Sustainable Pavement Systems: A Reference Document. FHWA-HI-15-002. FHWA, U.S. DOT, Washington, D.C. Stroup-Gardiner, M., and T. Wattenberg-Komas. 2013. NCHRP Synthesis 435: Recycled Materials and Byproducts in Highway Applications—Summary Report. Transportation Research Board of the National Academies, Washington, D.C.

Sustainable Construction Practices 103 9.15.1 Reduce Materials Use Effort (time and cost): Impact/Effort Ratio Human Welfare: Environmental Benefit: Cost Savings: Not Rated This SCP split out as a separate practice after the rating process was complete, so it is not rated. Not Rated Effort (time and cost): Impact/Effort Ratio Human Welfare: Environmental Benefit: Cost Savings: Not Rated This SCP split out as a separate practice after the rating process was complete, so it is not rated. Not Rated Summary Reduction in the use of materials can lead to a significant reduction in the energy and emissions related to the virgin material processing and transportation (Van Dam, Harvey, and Muench, 2015). Asphalt pavements designed for restricting the distress to the surface require fewer new materials as maintenance operations will involve replacement of the wearing/surface course alone, with base and subbase undisturbed. The use of alternative hydraulic cement and several co-products such as fly ash and micro silica reduce the amount of portland cement required. Retrofitting with dowel bars and grinding the old pavement extends the service life of concrete pavements that in turn reduces the amount of materials required (Washington State DOT, 2011). Key References Van Dam, T. J., J. T. Harvey, S. T. Muench, et al. 2015. Towards Sustainable Pavement Systems: A Reference Document. FHWA-HI-15-002. FHWA, U.S. DOT, Washington, D.C. Washington State DOT. 2011. Sustainability: Highway Materials. Title VI Statement to Public. 9.15.2 Reuse Existing Materials in Place Summary Reuse refers to removal and placement of the same material in a place. The primary differ- ence between reuse and recycling is that there is no alteration in the nature of material when it is reused. Existing pavements, base course, bridge abutments, and other exiting-infrastructure can be reused as-is and provide value to the project. For instance, the exiting pavement may be paved over but by being left in place (rather than removed), it provides valuable support to the new overlying pavement. Other forms of in-place recycling (processing in-place material but not removing it) are a hybrid of reuse and recycle and are discussed in Section 9.13.3). Key Reference Greenroads Rating System, v2. 2018.02.23. www.greenroads.org (see credit MD-1).

104 Sustainable Highway Construction Guidebook 9.15.3 Recycle Highway Materials Effort (time and cost): 2.0 Impact/Effort Ratio Human Welfare: 2.2 Environmental Benefit: 4.2 Cost Savings: 2.7 4.5 Summary The scarcity of quality aggregates, budget constraints, enhanced emissions, and disposal problems have contributed to increased use of recycled materials for both asphalt and concrete pavements. Examples of recycled highway materials include: • Reclaimed Asphalt Pavement (RAP) is used as a material in new HMA. In 2017 the aver- age percentage of RAP used in asphalt pavements in the United States was 20.5 (Williams et al., 2018); about one-fifth of all new asphalt pavements were recycled from old asphalt pavements. The use of RAP can reduce the need for virgin aggregate and asphalt binder in a mixture, which in turn directly contributes to a decrease in greenhouse gas emissions associ- ated with the mixture (Mukherjee, 2016). While the primary use of RAP is in new asphalt pavement (95%), it is also used in aggregate bases (4%), cold-mix asphalt (<1%), and even new concrete (<1%) (Williams et al., 2018). • Recycled Concrete Aggregate (RCA) is used as aggregate in new concrete and as a high- quality base material. RCA produced from crushing concrete has increased stiffness and enhanced properties as compared to the virgin aggregate (Chai, Monismith, and Harvey 2009). Coarse and fine RCA are both used in base and subbase layers. RCA can also be used for the lower lift in two-lift concrete pavement constructions. • Steel is a highly recycled product and its manufacturing process generates co-products use- ful to highways. Structural steel produced in the United States contains 93 percent recycled steel scrap, and can be recycled into new steel products with no loss of physical properties (AISC, 2018). Key References Williams, B. A., A. Copeland, and T. C. Ross. 2018. Asphalt Pavement Industry Survey on Recycled Materials and Warm-Mix Asphalt Usage: 2017. Information Series 138 (8th edition). National Asphalt Pavement Association, Lanham, Maryland. Mukherjee, A. 2016. Life Cycle Assessment of Asphalt Mixtures in Support of an Environmental Product Declaration. ISO 14040 compliant life cycle assessment study supporting the National Asphalt Pavement Association, EPD Program for North American Asphalt Mixtures. Chai, L., C. L. Monismith, and J. Harvey. 2009. Re-Cementation of Crushed Material in Pavement Bases. UCPRC-TM-2009-04. Caltrans, Sacramento, California. Van Dam, T. J., J. T. Harvey, S. T. Muench, et al. 2015. Towards Sustainable Pavement Systems: A Reference Document. FHWA-HI-15-002. FHWA, U.S. DOT, Washington, D.C. American Institute of Steel Construction. 2018. Why Steel: Sustainability. https:// www.aisc.org/why-steel/sustainability/#29353.

Sustainable Construction Practices 105 9.15.4 Use Co-Products and Waste Materials from Other Industries Key References Van Dam, T. J., J. T. Harvey, S. T. Muench, et al. 2015. Towards Sustainable Pavement Systems: A Reference Document. FHWA-HI-15-002. FHWA, U.S. DOT, Washington, D.C. American Coal Ash Association. 2013. ACAA 2011 CCP Survey Results. American Coal Ash Association, Farmington Hills, Michigan. Williams, B. A., A. Copeland, and T. C. Ross. 2018. Asphalt Pavement Industry Survey on Recycled Materials and Warm-Mix Asphalt Usage: 2017. Information Series 138 (8th edition). National Asphalt Pavement Association, Lanham, Maryland. Stroup-Gardiner, M., and T. Wattenberg-Komas. 2013. NCHRP Synthesis 435: Recycled Materials and Byproducts in Highway Applications—Summary Report. Transportation Research Board of the National Academies, Washington, D.C. FHWA. 2016. User Guidelines for Waste Byproducts Materials in Pavement Construction: Scrap Tires. FHWA-RD-97-148. https://www.fhwa.dot.gov/ publications/research/infrastructure/structures/97148/st4.cfm. Effort (time and cost): 2.0 Impact/Effort Ratio Human Welfare: 2.2 Environmental Benefit: 4.2 Cost Savings: 2.7 4.5 Summary Materials such as slag, fly ash, scrap tires, and reclaimed asphalt shingles (RAS) are considered waste in other industries, but have been used (1) as an additive to create desirable engineering properties or (2) as a replacement for virgin material in highway construction. Because these and other materials have been used with such success, they are sometimes considered co-products, which are products intentionally produced along with the main product and have independent value. Some common uses of co-products or waste material are: • Fly ash, a co-product/waste material from coal power plants, is used as supplementary cementitious material (SCM). Natural pozzolans and silica fume are also used as SCMs, but in smaller quantities (Van Dam et al., 2015). A 2011 study found that out of the 59 million tons of fly ash produced in the United States, 13 million tons were used in concrete and cement production (American Coal Ash Association, 2013). • Blast furnace slag, a co-product of steel production, is a common highway material. Ground granulated blast furnace slag (3.2 million tons in 2016 according to the United States Geological Survey) is combined with portland cement to produce slag cement or used as a cement replace- ment product. Air-cooled slag can be used to produce slag aggregate (5.8 million tons in 2016 according to the USGS). • RAS, a waste material in the roofing industry, can be ground up and used in small percentages as a partial asphalt binder replacement in asphalt pavements. Processing RAS and RAS binder quality are important issues. • Scrap tires can be ground or shredded into crumbs or chips to be used either as an additive to asphalt cement or as a lightweight fill material for roadways and behind retaining walls (FHWA, 2016).

106 Sustainable Highway Construction Guidebook 9.15.5 Use Alternate or Improved Materials Effort (time and cost): 2.4 Impact/Effort Ratio Human Welfare: 1.8 Environmental Benefit: 3.4 Cost Savings: 2.2 3.1 Summary This section discusses improvements in the material production process as well as use of alternative materials. Some examples are: • WMA production involves using an additive or process to produce asphalt at lower tempera- tures than that used to produce conventional HMA. It can reduce energy consumption and associated emissions during production (Williams, 2018). • Bio-binders are materials that can be used as alternatives to asphalt binder (a petroleum prod- uct), but are made from renewable natural resources such as agriculture and forestry residues. Example sources are swine manure (Fini, 2012) and mixed bio-oil with bitumen modifiers and extenders (Peralta, 2012). • Materials that function as pozzolans can be used to reduce portland cement use. Rice husk ash, which is produced during the processing of rice, is such a material. Many alternative materials are still in research, and not widely available or priced for mass use. Key References Williams, B. A., A. Copeland, and T. C. Ross. 2018. Asphalt Pavement Industry Survey on Recycled Materials and Warm-Mix Asphalt Usage: 2017. Information Series 138 (8th edition). National Asphalt Pavement Association, Lanham, Maryland. Fini, E., I. Al-Qadi, Z. You, et al. 2012. Partial Replacement of Asphalt Binder with Bio-Binder: Characterization and Modification. International Journal of Pavement Engineering, 13(6), 515–522. Peralta, J., R. C. Williams, H. M. R. D. Silva, and A. V. A. Machado. 2014. Recombination of Asphalt with Bio-Asphalt: Binder Formulation and Asphalt Mixes Application. Civil, Construction and Environmental Engineering Conference Presentations and Proceedings 77. 9.15.6 Local Materials Effort (time and cost): Impact/Effort Ratio Human Welfare: Environmental Benefit: Cost Savings: Not Rated This SCP split out as a separate practice after the rating process was complete, so it is not rated. Not Rated Summary There is an increase in the costs and emissions with the increase in the transportation distance between the source and the destination for a material due to increased fuel usage. Mukherjee (2016) showed that GHG emissions increased with the increase in the transportation distance

Sustainable Construction Practices 107 of RAP from source to plant. Hence, wherever possible it is advisable to use locally available materials. As part of the procurement process some states require the use of domestically manu- factured products, which can effectively reduce the distances traveled by the materials to site. For example, the Ohio Revised Code Section 153.011 requires the use of domestic steel products. Techniques such as in-place recycling can be used to reduce the transportation distance of some materials such as RAP and RCA. In such cases local materials are primarily used in base and subbase layers, as they may not meet the specifications to be used in the surface layer (Gautam, Yuan, and Nazarian, 2013). When considering substandard local materials in lieu of standard, more distant materials, the impacts on quality and durability must be carefully considered. Key References Gautam, B., D. Yuan, and S. Nazarian. 2013. Optimum Use of Local Materials for Roadway Base and Subbase. In Airfield and Highway Pavement 2013: Sustainable and Efficient Pavements, pp. 1348–1357. Mukherjee, A. 2016. Life Cycle Assessment of Asphalt Mixtures in Support of an Environmental Product Declaration. ISO 14040 compliant life cycle assessment study supporting the National Asphalt Pavement Association, EPD Program for North American Asphalt Mixtures. 9.15.7 Environmental Product Declarations (EPDs) Effort (time and cost): 2.8 Impact/Effort Ratio Human Welfare: 1.9 Environmental Benefit: 2.8 Cost Savings: 0.7 2.0 Summary EPDs are third-party verified documents that communicate the environmental impacts of a material using a cradle-to-gate life-cycle assessment (LCA). ISO 14025 (2006) and ISO 21930 (2017) provide a compliance regime for developing EPDs. EPDs can be used to benchmark impacts of a pavement or construction process, and in the long-run to consider improvements in design and construction to reduce impacts. The pavement construction materials industry has embraced LCA, and both the concrete and asphalt industries have developed ISO 14025 and EN 15804 compliant EPD programs. Additionally, the Buy Clean California Act (2017) requires successful bids to produce EPDs for a list of eligible materials before installing them. The use of EPDs in the highway industry is in its infancy but may become much more commonplace in the coming years. Key References ISO 14025. 2006. Environmental Labels and Declarations—Type III Environmental Declarations—Principles and Procedures. https://www.iso.org/standard/38131.html.

108 Sustainable Highway Construction Guidebook ISO 21930. 2018. Sustainability in Buildings and Civil Engineering Works. http:// www.iso.org/standard/61694.html. Assembly Bill No. 262. 2017. Public Contracts: Bid Specifications: Buy Clean California Act. https://leginfo.legislature.ca.gov/faces/billTextClient.xhtml?bill_ id=201720180AB262. Kanaras, K. 2018. NAPA EPD Program. National Asphalt Pavement Association. http://www.asphaltpavement.org/EPD. University of Washington. 2017. Concrete Product Category Rule: Establishing the Standard to Calculate EPDs. Carbon Leadership Forum. http://www. carbonleadershipforum.org/2017/01/03/concrete-pcr.

Sustainable Construction Practices 109 9.16 Safety Overview Safety is the condition of being protected from risk, danger, and injury which directly affect human health and life. Construction safety is regulated by federal and state agencies, including the Occupational Safety and Health Administration (OSHA). This category addresses worker safety actions beyond regulatory requirements. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity X Project Requirement X Goodwill X Motivations Sustainable Construction Practices • Sustainable Construction Safety and Health rating system. Rates projects based on the importance given to worker safety and health. • Job hazard analysis. Improves safety by actively identifying hazards and determining the safest way to do the work. • Automated flagger assistance devices. Improves worker safety by replacing flaggers who are typically located near traffic approaching a work zone. • Work zone intrusion warning systems. Technology used to notify workers and drivers of unauthorized vehicles entering work zones. • Unmanned aerial vehicle inspection. Provides visual inspection of highway and bridge construc- tion to assist workers in doing their work in a better and safer way. Sometimes, it also eliminates the need to expose a worker to risks associated with operating at height, such as on a telescopic lift. Principal Guidance, Assistance, and Tools FHWA. n.d. Worker Safety. https://ops.fhwa.dot.gov/wz/workersafety/index.htm. 9.16.1 Sustainable Construction Safety and Health Rating System Effort (time and cost): 2.6 Impact/Effort Ratio Human Welfare: 3.1 Environmental Benefit: 0.8 Cost Savings: 1.0 1.9

110 Sustainable Highway Construction Guidebook Summary The Sustainable Construction Safety and Health (SCSH) rating system is a construc- tion worker safety and health rating tool. While most sustainable rating systems consider occupant health and safety, the SCSH rating system rates projects based on the importance given to construction worker safety and health and the degree of implementation of safety and health elements. This rating system aims to unify and coordinate the safety and health efforts of the four primary parties—owner, designer, general contractor, and subcontractors in a project. The SCSH rating system consists of 50 safety and health elements organized into 13 categories. These categories are (a) project team selection, (b) safety and health in contracts, (c) safety and health professionals, (d) safety and health commitment, (e) safety and health planning, (f) training and education, (g) safety resources, (h) drug and alcohol program, (i) accident investigation and reporting, (j) employee involvement, (k) safety inspection, (l) safety accountability and performance measurement, and (m) industrial hygiene practices. Each category contains safety and health elements which carry credits based on their effectiveness in preventing construction worker injuries and illnesses. This rating system is validated based on the data from 25 construction projects (Rajendran and Gambatese, 2009). 9.16.2 Job Hazard Analysis Key References Rajendran, S. 2016. Sustainable Construction Safety and Health (SCSH) Rating System Version 1.0. http://sustainablesafetyandhealth.org/wp-content/uploads/ SCSH-Rating-System-1.0.pdf. Rajendran, S., and J. A. Gambatese. 2009. Development and Initial Validation of Sustainable Construction Safety and Health Rating System. Journal of Construction Engineering and Management, Vol. 135(10). Effort (time and cost): Impact/Effort Ratio Human Welfare: Environmental Benefit: Cost Savings: Not RatedNot Rated This SCP was added after the rating process was complete, so it is not rated. Summary A technique to analyze a job task and identify hazards to determine the safest way to perform the task. OSHA provides basic guidance on how to perform a job hazard analysis (OSHA, 2002). More detail guidance also exists (for example, Roughton and Crutchfield, 2008); however, job hazard analysis is generally not required by regulation. Key References OSHA. 2002. Job Hazard Analysis. OSHA 3071. Roughton, J., and N. Crutchfield. 2008. Job Hazard Analysis: A Guide for Voluntary Compliance and Beyond. Butterworth-Heinemann, Burlington, Massachusetts.

Sustainable Construction Practices 111 9.16.3 Automated Flagger Assistance Devices Effort (time and cost): 1.7 Impact/Effort Ratio Human Welfare: 3.1 Environmental Benefit: 0.2 Cost Savings: 1.5 2.7 Summary Automated flagger assistance devices (AFADs) are temporary traffic control devices that func- tion under the same operational principles as traditional flagging but remove the flagger from live traffic. Flaggers control AFADs by using a radio control unit or a cable directly attached to the AFAD from an area away from traffic, such as behind a guardrail. Key References Brown, H., C. Sun, S. Zhang, and Z. Qung. 2018. Evaluation of Automated Flagger Assistance Devices. Publication No. cmr 18-004. University of Missouri, Columbia, Missouri. American Traffic Safety Services Association. 2012. Guidance on the Use of Automated Flagger Assistance Devices. Fredericksburg, Virginia. 9.16.4 Work Zone Intrusion Warning Systems Effort (time and cost): 2.0 Impact/Effort Ratio Human Welfare: 3.3 Environmental Benefit: 0.2 Cost Savings: 1.2 2.3 Summary Technology is used to notify workers and drivers of unauthorized vehicles entering work zones. Intrusion alarms are most beneficial for temporary work zones with minimal separation from moving traffic. Sensors used can range from pneumatic tubes to impact sensors placed on traffic control devices to multiple sensors (video, radar, GPS) working in concert. Alarms are almost always audible, with some systems also using visual (flashing lights) and haptic (wearable units that vibrate) methods. Research and development of these systems is progressing rapidly. Current issues are (1) quantifying the resulting risk reduction, (2) minimizing false alarms, and (3) ensuring that drivers and workers notice and react to warnings. Key References Fyhrie, P. B. 2016. Work Zone Intrusion Alarms for Highway Workers. AHMCT Research Center for Caltrans, Sacramento, California. Gambatese, J. A., H. W. Lee, and C. A. Nnaji. 2017. Work Zone Intrusion Alert Technologies: Assessment and Practical Guidance. FHWA-OR-RD-17-14. Oregon DOT, Salem, Oregon.

112 Sustainable Highway Construction Guidebook 9.16.5 Unmanned Aerial Vehicle Inspection Summary Unmanned aerial vehicles (UAVs or drones) are aircraft operated without humans on board; they are controlled either autonomously or remotely. These devices can be outfitted with several sensors including GPS, high-resolution cameras, and LIDAR, and can be used as project inspec- tion tools. Safety benefits result from removing an inspector from dangerous field conditions (for example, inspecting a rock slope for stability). Effort (time and cost): 2.3 Impact/Effort Ratio Human Welfare: 2.3 Environmental Benefit: 1.4 Cost Savings: 1.1 2.1 Key Reference FHWA. 2013. Unmanned Aerial Vehicle Applications for Highway Transportation. FHWA-HRT-14-037. https://www.fhwa.dot.gov/publications/research/ ear/14037/14037.pdf.

Sustainable Construction Practices 113 9.17 Employment Overview Employment is an important impact that projects and participating organizations have on their communities. While there are many standard employment regulations, there are many more potential goals for organizations and projects that might include employee training time, employee turnover rates, parental leave policies, diversity, income equality, non-discrimination standards, freedom of association and collective bargaining, and local community participation. However, in the United States it is difficult for highway construction projects to influence these items. Nevertheless, the U.S. DOT’s Disadvantaged Business Enterprise (DBE) program and local employment opportunities can be addressed. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity X Project Requirement X Goodwill X Motivations Sustainable Construction Practices • Meet Disadvantaged Business Enterprise Goals. Meet current DBE goals. • Local Employment. Hire project personnel from the local area to help the local economy and alleviate local unemployment. Principal Guidance, Assistance, and Tools FHWA. 2018. Disadvantaged Business Enterprise Program (DBE)—Civil Rights. https://www.fhwa.dot.gov/civilrights/programs/dbess.cfm. Accessed July 2018. Cantrell, J. D., and S. Jain. 2013. NCHRP Legal Research Digest 59: Enforceability of Local Hire Preference Programs. Transportation Research Board of the National Academies, Washington, D.C. 9.17.1 Meet Disadvantaged Business Enterprise Goals Effort (time and cost): 2.2 Impact/Effort Ratio Human Welfare: 2.2 Environmental Benefit: 0.0 Cost Savings: 0.2 1.1

114 Sustainable Highway Construction Guidebook Summary The intention to meet or exceed the stated disadvantaged business enterprise (DBE) goal for a project should include women-owned and veteran-owned businesses. The DBE program is a legally required U.S. DOT program that applies to all federal-aid highway dollars spent on such recipients as state DOTs. The program’s purpose is to (FHWA, 2018): • Ensure nondiscrimination in the award and administration of DOT-assisted contracts, • Help remove barriers to the participation of DBEs in DOT-assisted contracts, and • Assist the development of firms that can compete successfully in the marketplace outside of the DBE program. Every 3 years, state DOTs are required to set DBE goals that they must meet or show good faith in pursuing. The DBE program has been subject to criticism, mainly for fraudulent claims of DBE status, limiting competition, placing an over-emphasis on DBE certification rather than helping, having no term limit on participation, and management issues (U.S. Office of Inspector General, 2013). Nevertheless, the DBE program’s goals are admirable. A sustainability effort should meet DBE goals, rather than just show good faith but fail to meet DBE goals. Key References FHWA. 2018. Disadvantaged Business Enterprise Program (DBE)—Civil Rights. https://www.fhwa.dot.gov/civilrights/programs/dbess.cfm. Accessed July 2018. U.S. Office of Inspector General. 2013. Audit Report: Weaknesses of the Department’s Disadvantaged Business Enterprise Program Limit Achievement of Its Objectives. Report No. ZA-2013-072. 9.17.2 Local Employment Effort (time and cost): Impact/Effort Ratio Human Welfare: Environmental Benefit: Cost Savings: Not RatedNot Rated This SCP was added after the rating process was complete, so it is not rated. Summary Hiring project workforce from the local area has been a part of construction agreements for quite some time. Local hiring clauses may encounter legal challenges on several grounds, but can be written so that the clauses withstand these challenges and are enforceable. Some ways of doing this are (Cantrell and Jain, 2013): • First source hiring agreements. These agreements require new or expanding businesses to hire (or try to hire) locally for temporary and permanent jobs. • Project labor agreements (PLA). Agreement to ensure labor peace by determining key terms of the hiring and working conditions ahead of time, which often includes local hiring requirements.

Sustainable Construction Practices 115 • Development agreement (DA). An agreement between a developer and a government entity that promises certain local benefits (that may include local hiring) in exchange for develop- ment permission. • Community benefits agreement (CBA). A contract between the developer and a coali- tion of community organizations pledging support in return for benefits including local hiring. One project example is the $367 million Washington State DOT SR 520 Pontoon Con- struction project (completed in 2015) located in Grays Harbor County, which had 13% unemployment at that time. It brought 300 construction jobs to the area, including 200 hires, of which 40% were from the local county (Seattle Times, 2 November 2011). Local employ- ment requirements probably do not greatly affect the bidding process. From 2015 to 2017 the FHWA’s SEP 14 Local Labor Hiring pilot program allowed participants to use social and economic hiring requirements (which have traditionally been disallowed due to concerns about their effect on competition) to evaluate their impact on the bid process. It focused spe- cifically on local hiring, and preferences for low-income and veteran workers. In all, 19 proj- ects (from 13 states) participated and generally noted no changes in bid price or competition (FHWA, 2018). Key References FHWA. 2018. Construction Program Guide: Special Experimental Project No. 14— Local Labor Hiring Pilot Program. https://www.fhwa.dot.gov/construction/cqit/ sep14local.cfm. Cantrell, J. D., and S. Jain. 2013. NCHRP Legal Research Digest 59: Enforceability of Local Hire Preference Programs. Transportation Research Board of the National Academies, Washington, D.C.

116 Sustainable Highway Construction Guidebook 9.18 Training Overview Knowledge is a vital organizational asset. A way to grow that asset is an investment in a valu- able commodity that produces high returns. Most organizations have some sort of training programs, and highway construction individuals are likely to participate in formal training. A recent (2014–2016) survey of the United Kingdom construction industry found the most com- mon training subjects to be: health and safety (79%), first aid (69%), asbestos awareness (52%), manual handling (51%), working at heights (47%), site management safety training (42%), and trade specific training (42%) (available at statista: https://www.statista.com/statistics/599835/ most-common-training-received-by-construction-workers-uk). Plenty of other training, usually called “informal training,” occurs outside the classroom, often in the form of on-the-job training. This section addresses a few training subjects that may be less popular but relevant to sustainability. General training approaches, programs, goals, and resources are necessary but not addressed here. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity X Project Requirement X Goodwill X Motivations Sustainable Construction Practices • Sustainability training. Train workforce on the general and specific sustainability objectives, commitments, and metrics in place for the project. • Sustainability credentials for individuals. Use credentialing as a third-party verification of training results. Principal Guidance, Assistance, and Tools Shiplett, M. H. 2006. NCHRP Synthesis 362: Training Programs, Processes, Policies, and Practices. Transportation Research Board of the National Academies, Washington, D.C. Laffey, N., and K. A. Zimmerman. 2015. NCHRP Synthesis 483: Training and Certification of Highway Maintenance Workers. Transportation Research Board of the National Academies, Washington D.C. NCHRP Project 02-25: Workforce 2030: Recruiting and Training the Next Generation Transportation Construction Workforce. NCHRP project, first advertised in 2018.

Sustainable Construction Practices 117 9.18.1 Sustainability Training Effort (time and cost): Impact/Effort Ratio Human Welfare: Environmental Benefit: Cost Savings: Not RatedNot Rated This SCP was added after the rating process was complete, so it is not rated. Summary Train the workforce on sustainability objectives, commitments, metrics, and concerns associated with the project. Sustainability is still a relatively new concept; it will likely take focused training to build workforce knowledge. Similar to how safety and environmental compliance training are done on projects today, sustainability training can be an orientation-level course given to new project per- sonnel that addresses key components of a project’s sustainability management plan (Section 9.4.4). The building industry can provide examples of sustainability training. It already has robust sustainability training programs focusing on the principles of sustainable buildings, document- ing construction work for rating systems (like Leadership in Energy and Environmental Design or LEED), and accreditation in such systems. Key References None. 9.18.2 Sustainability Credentials for Individuals Key Resources Greenroads Rating System, v2. 2018.02.23. www.greenroads.org. Envision v3. www.sustainableinfrastructure.org. Tulacz, G. 2018. The Top 100 Green-Buildings Contractors and Green-Building Design Firms, ENR, September 17, 2018. Effort (time and cost): Impact/Effort Ratio Human Welfare: Environmental Benefit: Cost Savings: Not RatedNot Rated This SCP was added after the rating process was complete, so it is not rated. Summary Most major sustainability rating systems offer accreditation/credential exams for individuals who wish to document their proficiency with the system. Typically, these exams can be preceded by courses (in-person or online) and may have multiple levels of achievement. They range from introductory accreditation, where the participant needs only to show rudimentary knowledge of the sustainability rating system and sustainability in general, to more advanced accreditation, where the participant might be required to manage the sustainability certification process on a project or perform the sustainability rating for a project. Usually, individual credentials are required and rewarded (with points) on projects pursuing certification through a third-party rating system. The building industry already participates heavily in individual credentialing: ENR (Tulacz, 2018) lists the top 100 green building contractors and counts over 10,000 “green accredited staff” among them.

118 Sustainable Highway Construction Guidebook 9.19 Community Outreach Overview An owner or a contractor needs to communicate and inform the stakeholders about the adverse effects of construction, as and when applicable, through multiple communication chan- nels and platforms, including but not limited to direct outreach, community participation, and social media applications. Communication plays an important role in ensuring traffic/road user safety and worker/job site safety, and in informing the surrounding community. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity X Project Requirement X Goodwill X Motivations Sustainable Construction Practices • Project outreach. In situations where a surrounding community is affected by a construction activity, the contractor needs to directly communicate with and reach out to the community to ensure participation, cooperation, and goodwill. Principal Guidance, Assistance, and Tools Warne, T. R. 2011. NCHRP Synthesis 413: Techniques for Effective Highway Construction Projects in Congested Urban Areas. Transportation Research Board of the National Academies, Washington, D.C. FHWA. 2017. Public Information and Outreach Strategies—FHWA Work Zone. https://ops.fhwa.dot.gov/wz/publicinfostrategies.htm. Shattuck, J., R. L. Clark, V. Ehikhamenor, et al. 2004. From Community Involvement to the Final Product: Marketing Mega Projects and the Public Trust (course text for TMAN 671, University of Maryland and FHWA). 9.19.1 Project Outreach Effort (time and cost): 2.3 Impact/Effort Ratio Human Welfare: 3.8 Environmental Benefit: 0.8 Cost Savings: 1.3 2.6

Sustainable Construction Practices 119 Summary Public outreach for highway construction projects is standard practice and can be a large factor in the public’s general attitude toward the project, owner, and contractors. Most large owners have public outreach policies and manuals that outline their approach. Often, contractors are either asked to participate in public outreach or even lead the effort. Typical metrics for public outreach success are minimal complaints or high public satisfaction through surveys. The following are suggestions for public outreach beyond stan- dard practice: • Hire a firm to manage interaction with the public. It is becoming more common to use a mar- keting firm with specialty experience in transportation projects to manage public interaction. • Construction communications plan. Provides a chain of command and delineates which people are responsible for what actions. • Use an ombudsman approach. An ombudsman is an official charged with representing the interests of the public (users and stakeholders). • Use social media and mobile applications. Minooei et al. (2016) found these to be the most effective for certain types of closures. Minooei et al. (2016) present a classification system-based impact time and anticipated capacity loss (lane reduction and time) that identifies which outreach strategies are most highly recommended for which conditions. For instance, for a full road closure less than one week in duration, the system would recommend as most effective: static temporary signage, variable sign boards, radio advertisements, television interviews, and social media. Key References FHWA. 2017. Program-Level Public Information and Outreach Examples. Work Zone Management Program. https://ops.fhwa.dot.gov/wz/publicinfostrategies/ programlevel.htm. Mallet, W. J, J. Torrence, and J. Seplow. 2005. Work Zone Public Information and Outreach Strategies. FHWA-HOP-05-067. FHWA, Washington, D.C. https://ops. fhwa.dot.gov/wz/info_and_outreach/index.htm. Minooei, F., N. Sobin, P. Goodrum, and K. Molenaar. 2016. State Transportation Agency Use of Community Outreach Tools on Accelerated Highway Construction Projects. Construction Research Congress 2016, pp. 1638–1647. Ehsaei, A., T. Sweet, R. Garcia, L. Adleman, and J. M. Walsh. 2015. Successful Public Outreach Programs for Green Infrastructure Projects. International Low Impact Development Conference 2015: LID: It Works in All Climates and Soils, pp. 74–92.

120 Sustainable Highway Construction Guidebook 9.20 Noise Overview Noise is unwanted sound. Construction noise affects human health through stress, hearing loss, sleep loss, fatigue, and interruptions, and it may also similarly affect wildlife. Noise can be mitigated by design for reduction at the source, along its path, and at the receiver. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Motivations Business Opportunity Project Requirement X Goodwill X Sustainable Construction Practices • Noise reduction based on ecological impact. Mitigate construction noise near/within habitat-sensitive areas to minimize ecological impact of noise. • Backup alarm modifications and alternatives. Boston CA/T project used adjustable noise alarms and spotters in place of traditional alarms for nighttime construction. • Use computer models to predict construction noise. Use the FHWA’s Roadway Construc- tion Noise Model (RCNM), or equivalent, to predict construction noise. • Reduce noise. Take measures to reduce noise more than the required minimum. Principal Guidance, Assistance, and Tools FHWA. 2006. Construction Noise Handbook. Publication No. FHWA-HEP-06-015. Office of Natural and Human Environment, Washington, D.C. https://www.fhwa. dot.gov/environment/noise/construction_noise/handbook. FHWA. n.d. Roadway Construction Noise Model—RCNM; Version 1.1. https:// www.fhwa.dot.gov/environment/noise/construction_noise/rcnm. University of Washington School of Public Health and Community Medicine. n.d. Occupational Noise and Hearing Conservation. http://depts.washington.edu/ occnoise.

Sustainable Construction Practices 121 Effort (time and cost): 2.6 Impact/Effort Ratio Human Welfare: 1.9 Environmental Benefit: 3.0 Cost Savings: 0.7 2.1 Summary While noise is usually treated as a human health concern, scientific research indicates it is also detrimental to wildlife and ecosystems (Shannon, et al., 2016), which is the primary con- cern in unpopulated areas. Animals can be sensitive to noise and alter their behavior because of it, and natural soundscapes are an important ecosystem feature. For instance, some species of birds will avoid noise sources such as highways or highway construction by up to three kilo- meters (Kaseloo and Tyson, 2004). For this reason, projects in sensitive areas might take steps such as not working during the two hours after sunrise and before sunset when birds are most active (Kaseloo and Tyson 2004). National Parks have directives to preserve the natural soundscape by minimizing artificial noise. For example, on a Western Federal Lands (WFL) road project in Mount Rainier National Park, the contractor was limited to 92 dB near West- ern Spotted Owl (listed as “threatened”) nesting areas and was required to use mufflers and limit idling time of construction equipment. 9.20.1 Noise Reduction Based on Ecological Impact Key References Kaseloo, P. A., and K. O. Tyson. 2004. Synthesis of Noise Effects on Wildlife Populations. Publication No. FHWA-HEP-06-106. Office of Research and Technology Services, FHWA, McLean, Virginia. Shannon, G., M. F. McKenna, L. M. Angeloni, et al. 2015. A Synthesis of Two Decades of Research Documenting the Effects of Noise on Wildlife. Biological Reviews, Vol. 91(4), pp. 982–1005. 9.20.2 Backup Alarm Modifications and Alternatives Effort (time and cost): 1.8 Impact/Effort Ratio Human Welfare: 3.4 Environmental Benefit: 1.3 Cost Savings: 1.1 3.1 Summary The Boston CA/T project used a variety of new noise control techniques. This project resulted in significant advances in backup alarm noise mitigation with adjustable noise alarms for night- time construction and use of spotters in areas sensitive to noise (Thalheimer, 2000). The major undertaking of the CA/T project spent only 0.13% of their budget on noise control, which for that project amounted to around $20 million. The cost of noise reduction can also vary based on what methods of control are used. For example, source control versus receptor control which is prohibitively expensive for minimal results. A benefit of noise control is that projects can be

122 Sustainable Highway Construction Guidebook completed on time. Without proper noise abatement strategies, complaints and possible legal issues may slow down project delivery. This helps to decrease the overall cost of the project as time is a valuable resource during construction. These benefits are confined to when the project is being built, as there are no tangible post-construction benefits from noise reduction during construction. Effort (time and cost): 2.9 Impact/Effort Ratio Human Welfare: 2.6 Environmental Benefit: 1.8 Cost Savings: 0.6 1.7 Summary In 2006, the FHWA released the Roadway Construction Noise Model (RCNM) that allows users to predict construction noise levels based on empirical data and acoustic propagation models. It is designed as a screening tool to predict construction noise with minimal project- specific data collection or input. Predictions can be useful in proactively developing noise mitigation measures in advance of construction activities rather than reactionary mitiga- tion measures based on stakeholder or neighbor noise complaints. The RCNM is based on a spreadsheet used during the Central Artery/Tunnel Project in Boston, Massachusetts. Effort (time and cost): 1.5 Impact/Effort Ratio Human Welfare: 2.9 Environmental Benefit: 1.8 Cost Savings: 0.6 3.5 Key Reference Thalheimer, E. 2000. Construction Noise Control Program and Mitigation Strategy at The Central Artery/Tunnel Project. Noise Control Engineering Journal. Vol. 48:5, pp. 157–165. 9.20.3 Use Computer Models to Predict Construction Noise Key References Schexnayder, C. J., and J. Ernzen. 1999. NCHRP Synthesis 218: Mitigation of Nighttime Construction Noise, Vibrations, and Other Nuisances. Transportation Research Board of the National Academies, Washington, D.C. FHWA. n.d. Roadway Construction Noise Model (RCNM) Version 2.0. https://www.fhwa.dot.gov/environment/noise/construction_noise/rcnm2 (computer model for predicting construction noise levels). 9.20.4 Reduce Noise

Sustainable Construction Practices 123 Summary Hearing loss is the top injury reported by highway construction workers. Additionally, noise is a major complaint by construction site neighbors. Generally, construction site noise is regulated by local ordinance to which some variations may be allowed. Sustainability gener- ally represents innovation in meeting or exceeding existing regulations. FHWA’s Construction Noise Handbook contains some basic ideas for mitigating construction noise during roadway construction. Key Reference FHWA. 2006. Construction Noise Handbook. FHWA-HEP-06-015. Office of Natural and Human Environment, Washington, D.C. https://www.fhwa.dot.gov/ environment/noise/construction_noise/handbook.

124 Sustainable Highway Construction Guidebook 9.21 Lighting Overview The International Dark-Sky Association (2017) defines light pollution as the “. . . inappro- priate or excessive use of artificial light.” They identify four components of light pollution: • Glare: excessive brightness that causes visual discomfort. • Skyglow: brightening of the night sky over inhabited areas. • Light trespass: light falling in unintended or unnecessary locations. • Clutter: bright, confusing, and excessive groupings of light sources. Light pollution affects human health and safety as well as ecological systems. While light can benefit society, excess light and light pollution can cause human issues (public displeasure, loss in aesthetic value, safety risks) and ecosystems (disruptions in natural mechanisms that regu- late plant flowering and growth, animal navigation, habitat fragmentation, and reproduc- tive behavior). This section addresses light pollution related to temporary lighting used during nighttime roadway construction and its contribution to light pollution. Typically, the focus is on creating adequate light for workers but reducing glare to improve driver safety, although some organizations, such as the National Parks, focus on ecological impacts as well. Motivations Business Opportunity Project Requirement X Goodwill Sustainable Construction Practices • Lighting plan. Describes equipment and operations needed for a nighttime lighting system. • Work zone glare reduction. Reduce glare experience by drivers by using light types and mounting strategies. • Semi-permanent high-mast lighting. Use tall (on the order of 100 ft.) lighting to reduce glare and setup time for longer duration construction (4 months or longer). Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Related Categories Principal Guidance, Assistance, and Tools American Traffic Safety Services Association. 2013. Nighttime Lighting Guidelines for Work Zones: A Guide for Developing a Lighting Plan for Nighttime Work Zones. Fredericksburg, Virginia (sponsored by FHWA).

Sustainable Construction Practices 125 Effort (time and cost): 1.9 Impact/Effort Ratio Human Welfare: 3.2 Environmental Benefit: 1.7 Cost Savings: 1.2 3.2 Summary The MUTCD, NCHRP Report 498 (Ellis, Amos, and Kumar 2003), and other guidance provide minimum standards for work zone lighting but often do not provide precise guidance on how best to achieve these standards. A lighting plan describes the equipment and operations needed for a nighttime lighting system. Some state DOTs have nighttime work zone lighting specifications and the FHWA offers basic guidance for developing a lighting plan in the absence of specifications (ATSSA 2013). Bullough et al. (2014) provide a checklist (page 69) for choosing appropriate light- ing based on project duration, tasks, complexity, traffic characteristics, and weather. Bullough, J. D. N. P. Skinner, J. D. Snyder, and U. C. Besenecker. 2014. Nighttime Highway Construction Illumination. Lighting Research Center, Rensselaer Polytechnic Institute for New York State DOT, Albany, New York (contains checklist for choosing appropriate nighttime work zone lighting: pages 69–72). Key References Ellis, R. D., S. Amos, and A. Kumar. 2003. NCHRP Report 498: Illumination Guidelines for Nighttime Highway Work. Transportation Research Board of the National Academies, Washington, D.C. American Traffic Safety Services Association. 2013. Nighttime Lighting Guidelines for Work Zones: A Guide for Developing A Lighting Plan for Nighttime Work Zones. Fredericksburg, Virginia (sponsored by FHWA). Bullough, J. D., N. P. Skinner, J. D. Snyder, and U. C. Besenecker. 2014. Nighttime Highway Construction Illumination. Lighting Research Center, Rensselaer Polytechnic Institute for New York State DOT, Albany, New York. 9.21.1 Lighting Plan Effort (time and cost): 2.2 Impact/Effort Ratio Human Welfare: 3.3 Environmental Benefit: 1.4 Cost Savings: 1.0 2.6 9.21.2 Work Zone Glare Reduction Summary Glare (excessive brightness) is the main work zone lighting safety concern for drivers. Glare can be reduced through planning, light positioning, and certain types of lighting equipment. General guidance to reduce glare are: • Use balloon lights. They result in 10% to 15% reduction of glare from conventional equipment but reduce illumination for workers compared to conventional lighting (El-Rayes et al., 2003).

126 Sustainable Highway Construction Guidebook Effort (time and cost): 2.5 Impact/Effort Ratio Human Welfare: 3.2 Environmental Benefit: 1.2 Cost Savings: 1.1 2.2 • Mount conventional lights higher and aim them downward (Hassan et al., 2011). • Aim conventional light towers away from oncoming traffic (Bhagavathula and Ronald, 2017). Key References Bhagavathula, R., and R. B. Gibbons. 2017. The Effect of Work Zone Lighting on Drivers’ Visual Performance. Transportation Research Record: Journal of the Transportation Research Board, No. 2617, pp. 44–51. El-Rayes, K., L. Y. Liu, L. Soibelman, and K. Hyari. 2003. Nighttime Construction: Evaluation of Lighting for Highway Construction Operations in Illinois. Publication No. ITRC FR 00/01-2. Illinois Transportation Research Center, Edwardsville, Illinois. Hassan, M. M., I. Odeh, and K. El-Rayes. 2011. New Approach to Compare Glare and Light Characteristics of Conventional and Balloon Lighting Systems. Journal of Construction Engineering and Management, Vol. 137(1), pp. 39–44. 9.21.3 Semi-Permanent High-Mast Lighting Summary Semi-permanent high-mast (on the order of 100 ft. tall) lighting can reduce construction time, glare, and setup time. Several DOTs have formally investigated its use and report gener- ally positive results. For example, Freyssinier et al. (2006) studied a New York highway con- struction project and determined that semi-permanent high-mast lighting costs 16% more than traditional lighting but saved substantial time each night as workers did not have to set up portable lighting. They recommend semi-permanent high-mast lighting for longer dura- tion projects only (about 4 months or longer) and pointed out issues with the clear zone (light towers must be close to the roadway, which may necessitate placing them in the clear zone) and light trespass (the height of light fixture may result in unwanted light in nearby business, residential, or ecologically sensitive areas). Key Reference Freyssinier, J. P., J. D. Bullough, and M. S. Rea. 2006. Documentation of Semi- Permanent High-Mast Lighting for Construction. Research Study C-05-06. Lighting Research Center, Rensselaer Polytechnic Institute for New York State DOT, Albany, New York.

Sustainable Construction Practices 127 9.22 Constructability/Deconstruction Overview Design for constructability (DfC) and design for deconstruction (DfD) collectively refer to the technical considerations of a highway’s design that can make it easier to construct, main- tain, salvage, or disassemble. In general, benefits of cost and schedule reduction drive DfC, while DfD is rarely a consideration in highways, but the principles are applied regularly in other industries including automobiles and buildings. Adaptive reuse can happen in bridge work, and deconstruction is usually driven by the value of recovered/recycled materials or the cost of landfilling if they were not recovered/recycled. Principal Guidance, Assistance, and Tools EPA. n.d. Design for Deconstruction. Washington, D.C. AASHTO and National Steel Bridge Association. 2016. G12.1–2016: Guidelines to Design for Constructability. AASHTO/NSBA Steel Bridge Collaboration. AASHTO. 2000. Constructability Review Best Practices Guide. AASHTO Subcommittee on Construction. Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Related Categories Motivations Business Opportunity Project Requirement X Goodwill Sustainable Construction Practices • Constructability reviews for projects. Formal design reviews to ensure they can be constructed using standard materials and methods, the plans/specifications are clear and non-conflicting, and the project can be reasonably be maintained over time. • Design for deconstruction. Design that specifically accounts for and makes easier decon- struction at end-of-life. • Adaptive reuse of structures. Reusing structures for a different purpose. • Deconstruction. Selective dismantling of infrastructure with the intention to reuse, repur- pose, and recycle it.

128 Sustainable Highway Construction Guidebook Summary The review process usually occurs during the design phase and is intended to ensure that (1) the design can be constructed using standard materials and techniques, (2) the plans and specifications provide clear, non-conflicting information, and (3) the project will result in something that can reasonably be maintained over time. Post-construction reviews can help correct problems encountered on future projects and are done by most state DOTs (AASHTO, 2000). Constructability reviews work for all project delivery methods, and many state DOTs have written constructability review processes. Benefits are typically lower construction cost because of fewer disputes, and more efficient construction techniques. 9.22.2 Design for Deconstruction Effort (time and cost): 2.8 Impact/Effort Ratio Human Welfare: 1.4 Environmental Benefit: 2.5 Cost Savings: 2.0 2.1 Effort (time and cost): 2.4 Impact/Effort Ratio Human Welfare: 1.8 Environmental Benefit: 2.1 Cost Savings: 3.1 2.9 9.22.1 Constructability Reviews for Projects Key References AASHTO and NSBA. 2016. G12.1-2016: Guidelines to Design for Constructability. Collaboration of AASHTO and National Steel Bridge Association. AASHTO. 2000. Constructability Review Best Practices Guide. AASHTO Subcommittee on Construction. NCHRP Project 10-99, Framework for Implementing Constructability across the Entire Project Development Process: NEPA to Final Design, is ongoing at the time of this publication. Summary Documented cases of DfD in highways are difficult to find. It may be that some current best practices embody principles of DfD but these practices are not commonly recognized as DfC. Concrete block pavements and, in some cases, precast concrete panels are used to make future utility access possible without demolition. Instead, the modular pavement is deconstructed and then replaced after work is complete. DfD should also carefully consider the future recyclability of materials added to infrastructure. How do glass, crumb rubber, sulfur, carbon fiber, and other industry byproducts affect the future recyclability of a pave- ment constructed with them?

Sustainable Construction Practices 129 9.22.3 Adaptive Reuse of Structures Effort (time and cost): 3.1 Impact/Effort Ratio Human Welfare: 2.0 Environmental Benefit: 3.5 Cost Savings: 2.1 2.5 Summary Reusing structures for a different purpose (for example, converting an industrial warehouse into loft apartments) can potentially have greater value than demolishing them (even if the demolished materials are recycled). Adaptive reuse is rare in highways with the notable exception of bridges. Washington State DOT’s SR 520 floating bridge across Lake Washington was decom- missioned from 2016 to 2017 using a combined deconstruction/demolition process. This process adaptively reused all 31 existing pontoon structures by selling them to a third party that had previously repurposed old pontoons for docks, artificial reefs, and wharfs. In 2011 the Torrence Avenue Vertical Lift Bridge rehabilitation project in Chicago adapted an adjacent abandoned railway bridge to be used by automobile traffic during the 9-month construction period, which eliminated a proposed 8-mile bypass (Kaderbek, Zsinko, and Burge; 2012). Missouri DOT even advertised an historic bridge that was made available for adaptive reuse: The Horse Creek Bridge in Vernon County is a 200 ft. long skewed Warren pony truss bridge, which was offered to potential recipients who needed to agree to move the structure and preserve the bridge in its new location. Key References None. Key References Washington State DOT. 2017. Decommissioning of Old SR 520 Floating Bridge: Sixties-Era Structure Now Removed from Lake Washington. Brochure from Washington State DOT SR 520 Bridge Replacement and HOV Program, Olympia, Washington State. Kaderbek, S., S. Zsinko, and D. Burke. 2012. Adaptive Reuse of the C&WI Railroad Vertical Lift Bridge, Chicago, IL. Heavy Movable Structures, Inc., 14th Biennial Bridge Symposium, 22-25 October, 2012, Orlando, Florida. Missouri DOT. n.d. Historic Bridge Available for Adaptive Reuse. Advertisement. 9.22.4 Deconstruction Effort (time and cost): 3.2 Impact/Effort Ratio Human Welfare: 1.9 Environmental Benefit: 2.9 Cost Savings: 1.8 2.1

130 Sustainable Highway Construction Guidebook Summary Deconstruction is the selective dismantling of infrastructure with the intention to reuse, repur- pose, and recycle all or part of the deconstructed item. Washington State DOT’s SR 520 float- ing bridge across Lake Washington was decommissioned from 2016 to 2017 using a combined deconstruction/demolition process. In addition to adaptive reuse of the pontoons, the following deconstruction was done: • Removing and recycling the asphalt pavement overlay on the bridge, • Removing and recycling the old bridge’s 58 anchor cables, • Demolishing and recycling the old bridge’s concrete structure, and • Deconstructing and recycling the old bridge’s 2 steel truss transition spans. The Canadian Institute of Steel Construction describes the deconstruction of the old Port Mann bridge in Vancouver, British Columbia and its sustainability impacts (Singh 2016). Overall, 9,000 tons of steel were recycled from the old Port Mann Bridge. Pavements can also be deconstructed in that they can be removed layer-by-layer instead of in bulk. For instance, although it may initially be more expensive to use several shallower milling machine passes rather than one deep one, there is value in removing the old pave- ment layer-by-layer to separate the asphalt pavement for recycling into RAP, the concrete for recycling into RCM, and the base material for reuse. If co-mingled, the material may be dis allowed even as fill material. Additionally, pavement layers of the same type can be separated to preserve recycling ability. For instance, the surface asphalt rubber layer can be removed separately from the underlying layers. Key References Washington State DOT. 2017. Decommissioning of Old SR 520 Floating Bridge: Sixties-Era Structure Now Removed from Lake Washington. Brochure from Washington State DOT SR 520 Bridge Replacement and HOV Program, Olympia, Washington State. Singh, R. F. 2016. The Port Mann Bridge: A Demonstration of Excellence in Reverse Erection Engineering. Advantage Steel, No. 56.

Sustainable Construction Practices 131 9.23 Quality Overview In the simplest of terms, quality is fitness for use. In construction, this means what is built must meet the requirements (specifications) of the owner. Garvin (1987) describes eight dimensions of quality: performance, reliability, durability, serviceability, aesthetics, features, perceived quality, and conformance to standards. Of these, highway construction has the highest impact on: • Reliability. How often do project items fail or require replacement? For instance, improper construction could lead to early failure of pavements, walls, or lighting. • Durability. This is the effective life of project items. Usually, quality is associated with long life. For instance, high construction quality may lead to fewer maintenance items as well as longer lasting walls, pavements, and fixtures. • Conformance to Standards. How well does what is built meet specifications? This certainly impacts reliability and durability, but it is also a measure of how closely the constructed project matches the design in every detail. Construction quality, and thus its contribution to reliability, durability and conformance to standards, can be measured, managed, and improved through purposeful actions. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Business Opportunity X Project Requirement X Goodwill Motivations Sustainable Construction Practices • Quality Management Plan. Use a quality management plan to formalize quality require- ments, compliance with acceptance criteria, responsible parties, quality assurance processes, quality measurement metrics, and quality control procedures. Principal Guidance, Assistance, and Tools Garvin, D. A. 1987. Competing in the Eight Dimensions of Quality. Harvard Business Review, Vol. 87, pp. 101–109.

132 Sustainable Highway Construction Guidebook Summary A quality management plan is intended to document the structure, responsibilities, and pro- cedures to effectively manage construction quality. Urban Engineers (2012) lists 15 elements of a quality management system as: (1) management responsibility, (2) documentation, (3) design control, (4) document control, (5) purchasing, (6) product identification and traceability, (7) process control, (8) inspection and testing, (9) inspection, measuring, and test equipment, (10) inspection and test status, (11) nonconformance, (12) corrective action, (13) quality records, (14) quality audits, and (15) training. Two key outcomes of following a quality management plan are (1) cost savings due to decreased conflicts and improved compliance and (2) waste reduction. Rath (2017) and Engineering Management Support (2017) provide two examples of how quality management plans are documented for transportation-related construction projects. Molenaar, K. R., D. D. Gransberg, and D. N. Sillars. 2015. NCHRP Report 808: Guidebook on Alternative Quality Management Systems for Highway Construction. Transportation Research Board of the National Academies, Washington, D.C. Urban Engineers, Inc. 2012. Quality Management System Guidelines. FTA-PA-27-5194-12.1. Federal Transit Administration, Washington, D.C. Key References Urban Engineers, Inc. 2012. Quality Management System Guidelines. FTA-PA-27-5194-12.1. Federal Transit Administration, Washington, D.C. Rath, T. 2017. Trans Mountain Expansion Project: Quality Management Plan. Document No. 01-13283-GG-0000-RPT-CM-0002. Kinder Morgan Canada, Inc. https://apps.neb-one.gc.ca/REGDOCS/File/Download/3179049. Engineering Management Support, Inc. 2017. Quality Management Plan: Globeville Landing Outfall Project. Prepared for City and County of Denver, Environmental Quality Division, Denver, Colorado. 9.23.1 Quality Management Plan Effort (time and cost): 2.2 Impact/Effort Ratio Human Welfare: 1.2 Environmental Benefit: 1.8 Cost Savings: 2.4 2.4

Sustainable Construction Practices 133 Motivations Business Opportunity X Project Requirement X Goodwill Sustainable Construction Practices • Tier 4 engines. Use Tier 4 diesel engines because of their reduced nitrous oxide and particu- late exhaust emissions. • Alternative fuels. Use alternatives to fossil fuel. They may have cost and environmental benefits. • Automated grade control. Use automated grade control in paving operations to improve efficiency and accuracy. • Vehicle idling policy. Limit vehicle idling time to reduce fuel consumption and resultant emissions. Principal Guidance, Assistance, and Tools FHWA. n.d. Design and Construction Strategies. https://ops.fhwa.dot.gov/wz/ construction/index.htm. EPA. 2018. Overview for Renewable Fuel Standard. Washington, D.C. https://www. epa.gov/renewable-fuel-standard-program/overview-renewable-fuel-standard. EPA. 2016. Greenhouse Gas Inventory Guidance: Direct Emissions from Mobile Combustion Sources. Washington, D.C. 9.24 Equipment Overview Equipment operation influences productivity, fuel use, and the health of workers and neigh- bors. These items directly influence pollution, resource consumption, and project cost as well as contribute to human health and happiness (for instance, construction noise may cause hearing loss in workers and annoyance and stress to neighbors). This section presents several sustainable practices that go beyond improving productivity. Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Related Categories

134 Sustainable Highway Construction Guidebook 9.24.1 Tier 4 Engines Effort (time and cost): 2.3 Impact/Effort Ratio Human Welfare: 2.7 Environmental Benefit: 3.2 Cost Savings: 1.0 3.0 9.24.2 Alternative Fuels Effort (time and cost): 3.0 Impact/Effort Ratio Human Welfare: 2.6 Environmental Benefit: 3.2 Cost Savings: 0.9 2.2 Summary Diesel from fossil fuel is the overwhelmingly predominant fuel source for construction equip- ment. However, price, environment, and future supply risks may make alternative fuels a viable option. Limited use of biofuel is already allowed, and research continues for other alternative fuels. B20 (20% biodiesel) is usually the maximum recommended for current diesel engines, but some specialty contractors use B100 (100% biodiesel) even though current costs and reduced power make it less competitive. Other alternative fuels must address refueling logistics and the high energy density fuel requirements for construction equipment. For example, while natural gas has gained in overall U.S. market share, it has an energy density that is 2 to 5 times less than diesel, which limits its use in heavy construction equipment. Summary From 2008 to 2015 EPA Tier 4 engines were phased in for non-road equipment. They reduce diesel NOx and particulate exhaust emissions by 90% from engines manufactured before the EPA rules. Existing equipment may continue to operate but new equipment must meet Tier 4 engine standards. While not yet common in highway construction, some projects place require- ments on the age and emissions performance of the project’s equipment fleet. Starting in 2018, large equipment fleets are prohibited from adding any more Tier 2 engine vehicles. Key Reference eCFR. 2018. Title 40: Protection of Environment, Part 1039—Control of Emissions from New and In-Use Nonroad Compression-Ignition Engines. Electronic Code of Federal Regulations. https://www.ecfr.gov/cgi-bin/text-idx?SID=43d03c9bee90888 02f63a72f3293a6f6&mc=true&node=pt40.36.1039&rgn=div5. Key References David, J. 2015. Growing the Demand for Biofuels in Off-highway Equipment Applications. For Construction PROS.com. https://www.forconstructionpros. com/equipment/fleet-maintenance/article/12056642/growing-the-demand-for- biofuels-in-offhighway-equipment-applications.

Sustainable Construction Practices 135 9.24.3 Automated Grade Control Effort (time and cost): 2.0 Impact/Effort Ratio Human Welfare: 0.9 Environmental Benefit: 1.6 Cost Savings: 2.0 2.3 Summary Hybrid laser-GPS systems are capable of tightly controlling paving and milling grades to high-level accuracy. While it is common to conduct earthwork using a 3-dimensional computer model and automated machine guidance, it is also beneficial for paving work with variable depth in paving and milling because it (1) saves the surveying step of marking variable depths on the pavement and (2) eliminates manual machine control required for variable elevation and cross- slope changes. Summary Many states have regulations that limit engine idling (a 2006 EPA accounting lists 30 states and D.C.). Many construction contracts also do; however, the federal government does not limit engine idling. Typical maximum allowed idle times are 15 minutes or less. Equipment idling uses fuel and emits pollution while the equipment is not engaged in productive work. In operations involving queuing (for example, asphalt mix delivery trucks), short allowable idle times can actually increase fuel use and emissions because of the delay and reduced production associated with stopping and starting equipment (Abbasian-Hoseini et al., 2016). In these cases, it is better to exempt queuing and similar tasks (for example, trucks waiting to offload asphalt mix) in the anti-idling specification. FPT Industrial. 2015. Fuel for Thought: Diesel Alternatives for the Non-Road Sector. For Construction PROS.com. https://www.forconstructionpros.com/ sustainability/article/12122157/fuel-for-thought-diesel-alternatives-for-the- nonroad-sector. Key Reference Unknown Author. 2012. All in a Weekend’s Work. In for Construction PROS.com. https://www.forconstructionpros.com/asphalt/pavers/article/10785573/automated- grade-control-system-holds-milling-and-paving-grade-during-fasttrack-paving- project. Effort (time and cost): 1.3 Impact/Effort Ratio Human Welfare: 2.7 Environmental Benefit: 2.9 Cost Savings: 2.1 5.8 9.24.4 Vehicle Idling Policy

136 Sustainable Highway Construction Guidebook Key References EPA. 2006. Compilation of State, County, and Local Anti-Idling Regulations. EPA420-B-06-004. Washington, D.C. Abbasian-Hosseini, S. A., M. L. Leming, and M. Liu, M. 2016. Effects of Idle Time Restrictions on Excess Pollution from Construction Equipment. Journal of Management in Engineering, Vol. 32(2): 04015046.

Sustainable Construction Practices 137 9.25 Utilities Overview Utility issues are a major cause of construction delays, and half of all highway construction projects eligible for federal funding involve utility relocation (Ellis et al. 2009). Sustainability issues regarding utilities focus on coordination and timely relocation of utilities. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Motivations Business Opportunity Project Requirement X Goodwill Sustainable Construction Practices • Integrating utilities into highway construction. The early consideration of utilities during highway design and maintenance scheduling can reduce the cost of relocation in later stages. Principal Guidance, Assistance, and Tools Quiroga, C., J. Anspach, P. Scott, and E. Kraus. 2018. Feasibility of Mapping and Marking Underground Utilities by State Transportation Departments. FHWA- HRT-16-019. FHWA, Washington, D.C. Anspach, J. H. 2010. NCHRP Synthesis 405: Utility Location and Highway Design. Transportation Research Board of the National Academies, Washington, D.C. 9.25.1 Integrating Utilities into Highway Construction Effort (time and cost): 2.5 Impact/Effort Ratio Human Welfare: 2.6 Environmental Benefit: 2.5 Cost Savings: 2.3 3.0

138 Sustainable Highway Construction Guidebook Summary Highway utility issues are largely viewed as a coordination problem that is largely solved in a project’s planning, administration, and design. However, AASHTO (2004) and transporta- tion research (Ellis et al., 2009; Anspach, 2010) also offer advice on construction-related issues including: • Relocate utilities in advance of construction. • Encourage/require utility companies to attend preconstruction meetings or hold a separate utility preconstruction meeting. • Consider non-financial items such as safety, environmental impacts, and community aesthet- ics for utility installations. • Consider cost sharing between owner and utility for relocations. This can be a general cost sharing or for specific features, such as paying utility companies for select clearing and grub- bing in exchange for relocation work done in advance of highway construction. • Consider incorporating utility relocation into the highway construction contract as it may improve contractor efficiency or schedule. • Provide utility issue training to owner, contractor and utility staff. • Maintain close (daily) coordination with utilities during construction. Key References AASHTO. 2004. Right of Way and Utilities Guidelines and Best Practices. Prepared by the Highway Subcommittee on Right of Way and Utilities in cooperation with FHWA. Ellis, R., M. Menner, C. Paulsen, et al. 2009. Integrating the Priorities of Transportation Agencies and Utility Companies. SHRP 2 Report S2-R15-RW. Transportation Research Board of the National Academies, Washington, D.C. Quiroga, C., J. Anspach, P. Scott, and E. Kraus. 2018. Feasibility of Mapping and Marking Underground Utilities by State Transportation Departments. FHWA- HRT-16-019. FHWA, U.S. DOT, Washington, D.C. Anspach, J. H. 2010. NCHRP Synthesis 405: Utility Location and Highway Design. Transportation Research Board of the National Academies, Washington, D.C.

Sustainable Construction Practices 139 Sustainable Construction Practices No viable SCPs were identified in this area. Related Categories Sustainability Construction Workers Project Delivery Method Work Zone Traffic Control Neighbors and Stakeholders Financing Materials Users Procurement Safety Pollution Contracting Employment Local Ecosystem and Habitat Scheduling Training Consumption Estimating Community Outreach Climate Project Controls/Administration Noise Project Budget Earthwork Lighting Maintenance and Operations Drainage/Sewer/Water Constructability/Deconstruction Economic Development/Employment Aesthetics Quality Walls Equipment Bridges Utilities Pavement Landscaping Motivations Business Opportunity Project Requirement X Goodwill 9.26 Landscaping Overview Landscaping, also known as roadside vegetation management, refers to any activity related to the protection, restoration, and rehabilitation of vegetation damaged or compromised by landscaping during transportation improvements, or simply to the enhancement of aesthetics in the corridors through landscaping.

Abbreviations and acronyms used without definitions in TRB publications: A4A Airlines for America AAAE American Association of Airport Executives AASHO American Association of State Highway Officials AASHTO American Association of State Highway and Transportation Officials ACI–NA Airports Council International–North America ACRP Airport Cooperative Research Program ADA Americans with Disabilities Act APTA American Public Transportation Association ASCE American Society of Civil Engineers ASME American Society of Mechanical Engineers ASTM American Society for Testing and Materials ATA American Trucking Associations CTAA Community Transportation Association of America CTBSSP Commercial Truck and Bus Safety Synthesis Program DHS Department of Homeland Security DOE Department of Energy EPA Environmental Protection Agency FAA Federal Aviation Administration FAST Fixing America’s Surface Transportation Act (2015) FHWA Federal Highway Administration FMCSA Federal Motor Carrier Safety Administration FRA Federal Railroad Administration FTA Federal Transit Administration HMCRP Hazardous Materials Cooperative Research Program IEEE Institute of Electrical and Electronics Engineers ISTEA Intermodal Surface Transportation Efficiency Act of 1991 ITE Institute of Transportation Engineers MAP-21 Moving Ahead for Progress in the 21st Century Act (2012) NASA National Aeronautics and Space Administration NASAO National Association of State Aviation Officials NCFRP National Cooperative Freight Research Program NCHRP National Cooperative Highway Research Program NHTSA National Highway Traffic Safety Administration NTSB National Transportation Safety Board PHMSA Pipeline and Hazardous Materials Safety Administration RITA Research and Innovative Technology Administration SAE Society of Automotive Engineers SAFETEA-LU Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (2005) TCRP Transit Cooperative Research Program TDC Transit Development Corporation TEA-21 Transportation Equity Act for the 21st Century (1998) TRB Transportation Research Board TSA Transportation Security Administration U.S. DOT United States Department of Transportation

TRA N SPO RTATIO N RESEA RCH BO A RD 500 Fifth Street, N W W ashington, D C 20001 A D D RESS SERV ICE REQ U ESTED ISBN 978-0-309-48095-6 9 7 8 0 3 0 9 4 8 0 9 5 6 9 0 0 0 0 N O N -PR O FIT O R G . U .S. PO STA G E PA ID C O LU M B IA , M D PER M IT N O . 88 Sustainable H ighw ay Construction G uidebook N CH RP Research Report 916 TRB