Sustainable Highway Construction (2019)

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16 instance, a project can identify sustainability objectives using the sustainability framework categories and can then choose relevant highway construction practices by using TABLE 9 to determine which highway construction categories of practices address the identified sustainability priorities. TABLE 9. Construction and Sustainability Framework Mapping 2.3 SUSTAINABLE CONSTRUCTION PRACTICES (SCPs) TABLE Level Category Project Delivery Method Financing Procurement Contracting Scheduling Estimating Project Controls & Administration Earthwork Drainage/Sewer/Water Aesthetics Walls Bridges Pavement Work Zone Traffic Control Materials Safety Employment Training Community Outreach Noise Light Constructability/Deconstruction Quality Equipment Utilities Landscaping Key: If a Highway Construction Category addresses a Sustainability Category, the corresponding cell is colored green Ec on om ic  De ve lo pm en t /   Em pl oy m en t Project Project Delivery Cl im at e Pr oj ec t B ud ge t Po llu tio n Lo ca l E co sy st em   an d  Ha bi ta t Co ns um pt io n W or ke rs Ne ig hb or s a nd   St ak eh ol de rs Us er s Highway Construction Framework Sustainability Framework Human Wellbeing Environment Wellbeing Economic Wellbeing M ai nt en an ce  a nd   Op er at io ns To view the SCPs Table, see Table 4 in NCHRP Research Report 916: Sustainable Highway Construction Guidebook (available at www.TRB.org by searching for “NCHRP Research Report 916”). 3 LITERATURE REVIEW The literature review examined 196 published sources and identified 64 sustainable construction practices (SCPs), which are listed in Section 8. 3.1 METHOD This section describes the literature review method to include the purpose, scope, definition of sustainability, and frameworks used to organize the findings.

17 3.2 PURPOSE The literature review purpose is to discover existing or experimental practices that could be considered SCPs. 3.3 SCOPE Literature reviewed includes:  Referred journal articles. Typically obtained through the Engineering Village 2 Compendex database, Google Scholar, and general web searches (e.g., Google, Bing).  Agency reports. Typically obtained through TRID (a combination of TRB’s Transportation Research Information Services (TRIS) Database and the OECD’s Joint Transport Research Centre’s International Transport Research Documentation (ITRD) Database) or general web searches (e.g., Google, Bing).  Organizational documents. Items such as policies, procedures and standard practices were reviewed only if publicly accessible on the web.  Construction documents. Typically obtained through general web searches (e.g., Google and Bing) or personal acquisition of construction documents by the research team.

18 3.4 ORGANIZATION OF THIS LITERATURE REVIEW This literature review was conducted before the original sustainability (TABLE 3) construction frameworks (TABLE 6) were revised based on feedback so it is organized according to these original frameworks and not the final revised versions. Thus, there are three major sections:  Program Level  Project Delivery Level  Project Level Program and Project Delivery sections are written as broad overviews, while the Project Level section is written as a category-by-category description. To the greatest extent practical, each section contains the following key items:  Definition. A succinct definition of the section subject.  Relationship to sustainability. The primary indicators (see TABLE 3) addressed by the SCP are listed in a tabular form. There may be more than one.  State-of-the-practice. Short description of common standard practice. This is necessary because SCPs are defined by their relationship to current regulation or standard practice. Recall that an SCP is one that (1) goes beyond the required national regulatory minimum or standard practice, or that (2) shows innovation in meeting these minimums and standards.  Innovative practices. Innovative practices described in the literature are summarized. These are used as a first draft of potential SCPs to include in the Guidebook. 3.5 PROGRAM LEVEL 3.5.1 Definition The program level addresses organization-wide approaches that can often take the form of organization strategy (regarding construction), general policy and project selection (building the right project, not just building it right), or broad management methods to achieve sustainable construction results. This section is written as a general summary of program level literature. 3.5.2 Organizational strategy, culture and executive support 3.5.2.1 Relationship to Sustainability  Dimension Category Indicator Human Wellbeing Personal & Social Development Education Equality Income Distribution Good Governance 3.5.2.2 Discussion  There is enough literature to suggest that organizational strategies, culture and executive support can all be used productively to (1) nurture conditions for sustainable construction practices within an organization and, (2) leverage better sustainability performance into better general performance as measured by cost and schedule performance.

19 Grounding their work in institutional theory, Jennings and Zandbergen (1995) argued the usefulness of this theory to promote ecologically sustainable organizations by explaining how organizations can build consensus around the meaning of sustainability and how sustainable practices are developed and diffused. Starting from a summary of the current thinking about the role of organizations in sustainability, which is shown in TABLE 10, the study developed a theoretical model relating sustainability to organizational elements and concepts. TABLE 10. Comparing Organizational and Ecological Views of Sustainability (Jennings and Zandbergen, 1995) Beheiry et al (2006) attempted to investigate the impact of organizational commitment to sustainability on capital project planning and capital project performance. Using data from large industrial and building projects, the research tested that a higher and balanced commitment to the three pillars of sustainability leads to better capital project planning and ultimately to better cost and schedule performance. The study also developed two indices for measuring the owner commitment to sustainable practices (Corporate Sustainability Commitment Index - CSCI) and the level of owner economic, environmental, and social planning and definition of large projects (Sustainability Component of Pre- Project Planning Index – SCPPI). These indices were found to be useful for measuring sustainability. Moreover, the study’s conclusions suggested that “corporate commitment to sustainability at the executive level is translating to better planning for sustainable project practices at the project definition level” (pp. 391) and that CSCI could be used as measure of “commitment to sustainability at the higher levels of multinational corporations” although it does need a more robust validation. Similarly, Jiang and Wong (2016) identified corporate social responsibility (CSR) activities and evaluated their suitability to the Chinese construction industry. Using a survey tool, the study identified key CSR activities, including environmental protection, construction quality and safety, community, employees, clients, and CSR management. The paper clearly recommends contractors to embed CSR activities in the construction process.

20 3.5.3 Policy/Program (Implementing Sustainability) 3.5.3.1 Relationship to Sustainability  Dimension Category Indicator Human Wellbeing Health & Happiness Safety Personal & Social Development Good Governance Environmental Wellbeing Nature & Environment Clean Air Clean Water Clean Land Ecological Resources Climate & Energy Renewable Energy Economic Wellbeing External Economy Employment 3.5.3.2 Discussion  Bossink (2002) studied how the interaction between public and private organizations in the Dutch construction industry have learned to interact to “develop and adopt sustainable construction innovations.” Focusing on data from a 10-year period on the residential building sector, this study found an industry-wide strategy to innovate sustainable construction. Public agencies established policies to stimulate and facilitate innovations by privates in demonstration projects to spurns diffusion among mainstream projects. Examples include “environmental policy plans, (inter)national R&D projects, design tools, demonstration projects, and laws and regulations […]. The public-private strategy is supported by public-private agreements, financial incentives and obstacles, waste management programs, environmental management systems, vision and ambition building, establishment of clear goals and implementation programs, communication with potential customers, and the development of sustainable competent by organizations in the construction industry” (pp. 22). Specific to the transportation sector, a recent study (Rangarajan, 2012) evaluated how to implement sustainability in transportation and infrastructure development projects through a trifold approach. First, the study develops a methodology for evaluating “the importance of project typology and selection for sustainable growth in rural and emerging settings.” This methodology integrates social, economic, and environmental factors to evaluate their implications early on in a project life cycle. Second, it develops a framework that “elevates sustainability as a primary consideration with emphasis on stakeholder involvement in the decision-making process.” Finally, it uses the Missouri State Rail Plan as a case study to showcase the proposed methodology. In spite of its interesting goals, the study seems incomplete as it only outlines generic claims of guidance for policy making efforts. Beginning with an investigation on sustainable construction practices and how their use may affect contractors’ competitiveness, Tan et al. (2011) found no cross-sectional relationship between sustainability performance and business competitiveness. Still, the extensive literature review performed by these authors identified a set of sustainable construction practices at the programmatic level as shown in TABLE 11. Assuming a longitudinal relationship between business competitiveness and current sustainability performance, the study develops an implementation framework to “help contractors develop their sustainable strategies for meeting a changing competition environment.” In spite of its intended claims, the study fails to validate this

21 framework and only outlines generic claims of guidance “for contractors to develop their sustainability policy, strategy and practice for meeting the increasing requirement for sustainable development in construction.” TABLE 11. Sustainable Construction Practices (Tan et al. 2011) Whereas commonly used highway construction practices may be sustainable, many of the sustainable construction practices are instead new to the agency adopting them. As a result, their implementation requires the agency to change its way to carry out business and to rely on best practices for implementing any innovation in organizations like transportation agencies, including securing executive support and developing a sustainable strategy. An example of statewide roadmap for a sustainable strategy is depicted in the Third Progress Report on State Green Procurement and Agency Sustainability by the Office of General Services in New York (NY) State. Analyzing statewide implementation of sustainable practices, this report provides an overview on implementation status for different NY state agencies, including the NY Department of Transportation (NY-OGS, 2015). This report outlines both goals and interim results, such as that construction and demolition recycling had reached 52% of the total amount of recycled materials. Notably, the report also outlines shortfalls, such as “Another area of difficulty is in sub-lease situations or construction processes, when one agency performs the work within a building or building project owned by another agency” (pp. 25). At the local level,

22 an example of institutionalizing a strategy and show executive support is the sustainability management plan (SMP) developed by the Greater Orlando Aviation Authority (GOAA) for 2014-2020, which was used to develop a roadmap grounded in GOAA values of “Innovation, Sustainability and Flexibility,” “Fiscal Responsibility” and “Collaborative Relationships” to be implemented by an ad-hoc team. GOAA SMP was based on a definition of sustainability as “the responsibility to construct and operate our airport facilities in a manner that ensures future generations will enjoy the same environment that we experience today. Sustainability efforts are achieved by a balance between the environment and community outreach, and the economics of managing the airport” (GOAA, 2014; pp.5). This plan included among its initiatives, some that closely related to construction, including (a) Reduce Solid Waste to Landfills; (b) Reduce Energy Use Intensities; (c) Reduce Water Consumption; and (d) Improve Sustainable Construction, Engineering and Design Practices. The last group of initiatives lists several examples of SCPs. The GOAA’s SMP is a neat example of how executive support was used to promote a sustainable strategy and convey it into specific practices. USDOT (2015) outlines USDOT’s achievements and plans to evolve into a sustainable organization. The report is not specific to construction activities. Still some of the information pertains to construction, including: (a) data on construction and demolition waste that has been diverted from landfills; (b) net-zero goals for construction of new buildings; (c) integration of electric vehicle recharging stations in all new buildings; (d) requirement to incorporate “all applicable sustainable acquisition requirements for recycled, bio-based, energy efficient, and environmentally preferable products” in every construction contract; and (e) goal of establishing “a tracking and reporting system for construction and demolition debris elimination.” 3.5.4 Human Resources Minimal to no literature to review. 3.5.5 Environmental Management Systems 3.5.5.1 Relationship to Sustainability  Dimension Category Indicator Environmental Wellbeing Nature & Environment Clean Air Clean Water Clean Land Ecological Resources Natural Resources Water Resources Consumption Climate & Energy Renewable Energy GHG Emissions 3.5.5.2 Discussion  Preserving and restoring ecosystems surrounding highways is one of the characteristics for a construction practice to be sustainable. Among these practices, Environmental Management Systems (EMS) have been used by transportation agencies to institutionalize standardized environmental practices. AASHTO has defined EMS as the “organizational structure, associated responsibilities, and procedures to integrate environmental considerations and objectives into the ongoing management decision-making processes and operations of an organization” (AASHTO,

23 2006; pp. 3). In 2006, a report investigated “the utility of EMS as a strategic planning tool for implementation of an organization's environmental priorities” [AASHTO; pp.3]. This study found that between 2003 and 2006 the number of transportation agencies that had implemented or were implementing EMS increased from 20% to 54% of the respondents. Whereas the study confirmed an increasing push towards EMS implementation, respondents manifested their concerns about ISO 14000 being an overkill or scarcely useful for public agencies and entities. The 2006 study resulted in a series of recommendations, lessons learned and a set of case studies for 12 state departments of transportation. Case studies reported information on EMS objectives, functional focus, status of implementation, accomplishments and benefits as well as implementation needs and keys to EMS development and success. 3.6 PROJECT DELIVERY LEVEL 3.6.1 Definition The project delivery level addresses systems and processes used to execute the contracting and procurement necessary to achieve project objectives. Importantly, it refers to (1) a specific project rather than an entire organization, and (2) contracting- and procurement-related processes rather than the specifics of estimating, scheduling, and construction means and methods. This project uses the following definitions related to project delivery.  Project delivery: the process of achieving project objectives.  Project delivery method: the contractual relationship among the key stakeholders in the project. Namely, the owner, designer, and constructor.  Procurement: the process of purchasing external services and materials necessary to deliver a project.  Contracting: the process of establishing a contract for services and materials. 3.6.2 Project Delivery Method The “project delivery method” refers to the contractual relationship between the key stakeholders in the project: the owner, designer, constructor, and (if included) construction manager. 3.6.2.1 Relationship to Sustainability  Dimension Category Indicator Human Wellbeing Personal & Social Development Good Governance Economic Wellbeing Project Economy Cost-Benefit 3.6.2.2 State‐of‐the‐Practice  The following project delivery methods are commonly defined (AGC, 2017; CMAA, 2008) used:  Design-bid-build (DBB). The owner holds separate contracts with the designer and constructor. The project is completely designed and then a bidding process is used to select the builder. CBB characteristics are: o Owner has the most control over design and construction, but such control requires expertise. o Design is complete prior to construction, but the owner assumes the design risk with the constructor.

24 o Construction cost is fixed at contract award. o Creates competition for low price among bidders, but may incentive bidders to omit items in order to decrease bid amount only to recover those costs in change orders later. o Easy to implement because it is commonly understood by all parties.  Design-build (DB). The owner enters into a contract with a single entity for the design and construction. Many forms of DB exist, depending upon other actions that may be undertaken by the designer/constructor such as finance, operation, maintenance, etc. DB characteristics are: o Less owner control. Typically, the owner specifies end results and constraints but allows for design and construction innovation in the DB’s approach, which can result in savings through efficiency and design/construction coordination. o Construction can start before design is finished, which may result in quicker project completion. o The DB entity assumes a relatively high amount of design and construction risk, but is usually given more flexibility in design and construction, which could potentially mitigate that risk. o Better communications between design and construction. One can influence the other and vice versa since both are controlled by the same DB entity.  Construction manager agency (CM agency). The owner maintains a separate contractual relationship with the designer and builder but retains a CM to manage the construction without assuming the risk of delivery. CM agency characteristics are: o The expertise required to manage construction, which the owner may not possess, is supplied by the CM agency.  Construction manager at-risk (CM at-risk). The owner has a separate contractual relationship with the designer and CM at-risk entity, whose responsibilities usually include advising the owner/designer during design, hiring and managing entities for the construction process, and working assuming cost and schedule risk. CM at-risk characteristics are: o Cost and schedule risk are transferred to the CM at-risk entity, which often enters into a guaranteed maximum price (GMP) contract with the owner. o The CM at-risk entity has total control over construction and subcontractors. 3.6.2.3 Innovative Practices  Ardani, Mallela, and Hoffman (2009), Binney (2014), Klotz & Horman (2010) have used innovative techniques to incorporate sustainability in the project delivery stage of pavement construction. Ardani, Mallela, and Hoffman (2009) used Construction Manager-General Contractor (CMGC) method for the 4500 South Bridge on State Route (SR) 266 in Salt Lake City, UT. The method made use of design-bid-build project delivery strategy that led to early involvement of contractor in the project. As a result, the duration of the project was reduced to 53 hours and saved about 36% of the total cost. Klotz & Horman (2010) performed a counterfactual analysis (comparing what actually happened vs. what would have happened in the absence of the investigated intervention) for the delivery of Pennsylvania State University’s Stuckeman Family and Forestry buildings through six steps namely mapping the delivery process, specifying the counterfactual, defining the scope of the counterfactual, setting up quantitative impact study, performing quantitative impact study and performing qualitative cost

25 study. The study revealed that counterfactual analysis can be used to deliver a sustainable construction project. To provide accountability for the whole construction ecosystem, Boz and El-Adaway (2014) developed three benchmarks to assess sustainability of civil infrastructure projects. These benchmarks are intended to create alignment within the construction industry towards recognizing technical, environmental, economic, social/cultural and individual indicators of construction sustainability. Using two different types of civil infrastructure projects, this study tested and evaluated the benchmarks and found “that benchmarks, indicators, and other elements within a single construction project can cross boundaries and overlap with one another” (pp. 04014019-11). The relationship between integrated contracts and sustainable outcomes of road infrastructures was also studied by Lenferink et al (2013). The study is strongly grounded in the alternative concept of inclusiveness, which is evaluated along three dimensions: (a) “the inclusion of actors in the planning, contracting and implementation process”; (b) “the spatial inclusion of other socio-economic functions in road infrastructure development, shifting the project focus from infrastructure itself to the combination of infrastructure and the surrounding area”; and (c) “the integration of stages in the project lifecycle” (pp. 618). Focused on assessing Dutch Design- Build-Finance-Maintain (DBFM) projects through interviews with project, this study supported the initial claim that contract integration is expected to lead to more sustainable infrastructure. The study concludes by recommending green procurement, strategic asset management and relational contracting as three pathways towards sustainable infrastructure development. Where studies on road sustainable practices are scarce, several studies of the building and industrial sectors were performed that are somehow relevant to our work, including studies on the overlap between lean and sustainable construction, on the relationship between delivery methods and practices and sustainable outcomes. Initial efforts were focused on the overlap between lean construction and sustainable construction. Focusing on the implementation of lean practices in construction, Lapinski et al. (2006) used a post hoc process-based analysis to study value and waste in a sustainable building project delivered by Real Estate and Facilities Division of Toyota Motor Sales. Similarly, Klotz et al (2007) outlines a detailed modeling protocol for evaluating the delivery processes of green projects while using modeling protocols adopted from lean construction. Another line of work included several studies on the relationship between delivery methods and practices and sustainable outcomes. Klotz and Horman (2010) investigated claims that project delivery affects sustainable performance of construction projects through counterfactual analysis. The study developed a methodology for investigating which project delivery attributes are most influential to sustainable outcomes and how the influence of these attributes be quantified. Where the methodology was used to evaluate several building projects on the Pennsylvania State University campus, this study did not produce conclusive findings. More extensively, Molenaar et al. (2009) performed a comprehensive study to evaluate how project delivery methods can contribute to sustainable building projects. Using the Leadership in Energy and Environmental Design (LEED®) certification as a measure of sustainability, the study found that integrated project delivery methods are crucial to building performance, and that early involvement by contractors is necessary to meet sustainable objectives.

26 In 2011, Swarup et al initiated work to evaluate the “influence of project delivery attributes, such as owner commitment, team integration, and contractual relationships” on project sustainability goals (pp. 1043). Using data from 12 green office buildings in the United States, this study identified several attributes crucial to achieve sustainability goals, including a “strong owner commitment towards sustainability, the integration in the delivery process by an early involvement of the constructor, and the early inclusion of green strategies.” Building upon this work, Mollaoglu-Korkmaz et al. (2013) studied the relationship, including the mediating factor of integration in delivery. The study adopted a comparative case study approach to conclude that delivery integration affects overall project outcomes, especially sustainability. While confirming that some delivery methods are expected to provide a better ground for integration, this study also found that the traditional design-bid-build method can achieve higher integration through the implementation of features, such as early contractor involvement, design charrettes, project team member’s compatibility, and commitment to project sustainability goals. Grounded on these studies, Gultekin et al. (2013) used a quantitative methodology to find statistical significance for some of the suggested project delivery features, including “use of design-build project delivery method, having an owner-initiated vision statement with sustainability goals, having all relevant project parties in design charrettes, running energy and lighting simulations preferably in conceptual design but no later than schematic design phase, owner’s capabilities on scope definition and decision making, selecting contractors from a restrained pool, and having the contractor involved at design development or earlier” (pp. A4013005-7). A case study (Wang et al., 2014) found that a form of public private partnership (PPP) made the private contractor more accountable for its sustainable outcome. Also, the whole life project management approaches that can occur under some PPP delivery methods contributed to seven sustainable attributes, including environmental management, community engagement, health and safety, whole life costing, waste management, and energy efficiency. The study produced a catalog of strategies for sustainable project management and identified six strategies that could be more transferable across different types of projects, including the use of a mix-experienced design team, design for whole life costing, service deduction mechanisms, whole life project management, regular operational monitoring, and effective communication. A few studies of industrial projects are relevant to our study and provide information on the nexus between project delivery and sustainability. Yates (2014) performed a study for the Construction Industry Institute. The study broadly investigated the topic of design and construction for sustainable industrial construction. The study produced models designed to help evaluate the level of project sustainability. These models incorporated several practices for achieving project sustainability at various project phases, including procurement and construction.  3.6.3 Project Procurement 3.6.3.1 Definition  Procurement is the process of purchasing external services and materials necessary to deliver a project.  

27 3.6.3.2 Relationship to Sustainability  Dimension Category Indicator Human Wellbeing Personal & Social Development Education Equality Income Distribution Good Governance Economic Wellbeing Project Economy Cost-Benefit 3.6.3.3 Innovative Practices  Specifying sustainability. Previous studies have suggested that team integration and early contractor involvement are crucial to sustainable outcomes. However, these factors are rarely implementable without adopting a multi-criteria procurement approach and certainly by adopting a low bid procurement, which can be open to ethical issues. Without focusing on sustainability, Aliza et al. (2011) performed a detailed literature review to develop an approach for ensuring transparency in decision making as well as accountability of the decision makers to the stakeholders. Another study (Xia et al. 2014) evaluated how public building owners in the U.S. convey sustainability requirements in their tender documents. The study found the Leadership in Energy and Environmental Design (LEED) certification to be prevalent in the decision making reaching a weight of up to 25% in best value evaluation formulas. Also, tenders based on incomplete design allocates higher importance on sustainability requirements as a way to motivate proposers to achieve these sustainable outcomes when they cannot be conveyed through a detailed design package. Focusing on design-build tenders, Xia et al. (2015) found that DB owners emphasize innovative technical solutions over past performance. The study also found that owners specifying LEED certification among their requirements tend to incorporate less design details in their tender documents as a way to solicit innovative design by the proposers. Alternative technical concepts (ATC). One of the major approaches for soliciting innovative solutions during procurement of highway projects is to allow for submission of ATCs. ATCs have been used by project owners to retain monetary savings of value engineering solutions when they are submitted during procurement while providing a competitive advantage to the proposer. Still, a recent TRB synthesis study (Gransberg et al., 2014) found that ATCs not only allowed agencies to achieve monetary savings, but also to encourage green techniques and achieve a sustainable outcome higher than that required in the initial tender documents. 3.6.4 Contracting 3.6.4.1 Definition  Contracting is the process of establishing a contract for services and materials with the contractors selected by procurement. 3.6.4.2 Relation to Sustainability   Dimension Category Indicator Human Wellbeing Personal & Social Development Education Equality Income Distribution Good Governance Economic Wellbeing Project Economy Cost-Benefit

28 Selecting a firm based on their expected performance does not guarantee the achievement of the project objectives in term of sustainability. Therefore, developing a contract that clearly conveys rights and expectations is as crucial as selecting the right firm. To this end, several studies evaluated the impact of contracting on the achievement of sustainable outcome and the promotion of sustainable construction practices. Another study funded by the Construction Industry Institute (O’Connor et al., 2016) introduces 54 sustainability actions to be implemented throughout the construction phase, including five during the contracting phase. Using a survey, the study found a widespread and increasing adoption of these actions within the industry. 3.7 PROJECT LEVEL 3.7.1 Definition The project level addresses practices selected within individual projects such as choices in materials, means and methods, safety and even employment. 3.7.2 Scheduling 3.7.2.1 Definition  A construction schedules provides a plan for completing a project based on spatial, temporal and resource constraints between activities expressed through activity durations and precedence relationships. 3.7.2.2 Relationship to Sustainability  Dimension Category Indicator Economic Wellbeing Project Economy Cost-Benefit Shorter and more efficient construction schedules can reduce costs and environmental impacts of construction. The use of diesel equipment for construction activities is one of the major causes of pollutant emissions (Waris et al. 2014). Lewis and Rasdorf (2016) determined that a fuel factor of 0.2 L/kWh is valid for heavy diesel equipment. Tang et al. (2013) showed that disruptive events in construction schedules can increase project GHG emissions. Similarly, Lewis, Shan, and Hazzard (2015) report that reallocation of resources and rescheduling of activities can reduce the formation of ground-level ozone. 3.7.2.3 Innovative Practices  A series of studies [D. Gilley et al. (2009), Bhajandas and Mallela (2013), Mallela et al. (2010), Littleton and Mallela (2013), Bhajandas and Mallela (2013), Raghunathan, Sadasivam and Mallela (2014)] were carried out by the U.S. Department of Transportation through the Longer- lasting highway infrastructure using Innovations to accomplish the Fast construction of Efficient and safe highways and bridges (LIFE) program, to evaluate the economic benefits of using accelerated bridge construction (ABC) techniques. Some examples are: 1. D. Gilley et al. (2009) reported that an accurate survey of fittings and timely available materials can reduce delay costs and translate into savings of $2.16 million. 2. Bhajandas and Mallela (2013) reported that by using precast concrete arch with varying gravel over top and bituminous pavement, lane closures could be reduced to 33 days instead of six months, saving 38% of the costs.

29 3. Mallela et al. (2010) reported savings of 32% of total project cost for bridge replacements on MD 28 and MD 450, Fredrick County and Anne Arundel County, Maryland by using ABC techniques. 4. Littleton and Mallela (2013) reported savings of 29% project cost by using ABC program on US 6 over Keg Creek. 5. Raghunathan, Sadasivam, and Mallela (2014) show that use of geo-synthetic reinforced soil-integrated bridge system with ABC lateral bridge slide saves 50% of the construction time and 8% savings on the total cost of the project. 6. Bhajandas and Mallela (2013) saved 7% cost for the replacement of Baltimore-Maryland bridge superstructure by using the self-propelled modular transporter. Each of these ABC methods is useful for reducing construction time and therefore likely to reduce the environmental impacts associated with increased site equipment emissions and traffic emissions due to work zone delays. Hence, the economic benefits of ABC techniques and the LIFE program can improve the overall economic and environmental outcomes of a construction project while improving project cost and duration outcomes. Cable and Frentress (2004) reported various advantages of using the two-lift paving technique in the United States and across the world. Two-lift paving helped in reducing the costs and time associated with the construction of pavement by using local and recycled materials. Tompkins et al. (2009) show that two-lift paving helped in reducing life-cycle costs through case studies in Austria and Germany. Prowell, Hurley, and Crews, (2007) stated that the use of warm mix asphalt (WMA) will lead to reducing construction schedule with same structural properties as that of hot mix asphalt (HMA). 3.7.3 Estimating 3.7.3.1 Definition  Cost estimating involves predicting the approximate costs and resources needed to complete a project (PMBOK, 2004). Cost estimates often include an indication of accuracy. Because they are predictive, cost estimates often address risk and uncertainties. Cost estimates employ both past experience and future forecasting, and are typically determined using the following inputs: (1) a quantification of necessary project resources, (2) schedule, (3) external resource limitations, and (4) forecasts of future conditions at the time of construction. The scope of this discussion is limited to means and methods to gather input data for a cost estimate, and the tools and information used to generate a cost estimate. Specific techniques, data sets, and software used in private sector cost estimating are often considered proprietary or trade secrets, therefore discussion is limited to general, publicly available information. 3.7.3.2 Relationship to Sustainability  Dimension Category Indicator Economic Wellbeing Project Economy Cost-Benefit Sustainability in construction estimates leads us to use of newer technologies whose results would be more accurate and the selection of the practices which have minimum impact on the surrounding environment (i.e. human, ecological).

30 Cost-benefit by design. Design of a facility is one of potential sources to cost savings. Some of the suggested practices are as follows:  The efficiency of the infrastructure, for example, minimizing the length of the sewer and utilities pipelines, the surface area for paving.  Reducing the usage of mechanical and electrical equipment and consumption of power through natural daylight, ventilation, low or no flow plumbing fixtures, etc.  Use of locally available and reclaimed material which boosts local economy and also decreasing the transportation costs.  Reducing or not using material for interior finishing’s, etc. Cost-benefit by improvising the construction process. Overall cost of the project can be reduced by using environmentally conscious practices thereby improvising environment and reduced use of natural resource during construction.  Usage of demolition debris  Repair and replacement costs can be reduced by protecting the equipment and material  Site restoration cost can be reduced by managing the access to the site and travel path  By minimizing deficiencies and improved occupying facilities can reduce the commission cost Life-cycle cost savings. Life-cycle costing quantifies the total costs and benefits over the life of a particular product, technology or system. The life cycle cost savings are predominantly due to reduced utility costs such as cost of energy and water, maintenance and operation costs. 3.7.3.3 State‐of‐the‐Practice  The building/construction documents are acquired from the designers. Files are viewed using software like Dodge viewer and printed. On-screen take offs are carried out using CAD tools or software like Bluebeam. Costs including contingencies and wastages are calculated. The cost outputs are checked with the industry cost data and adjusted by using factors defined by RS means (software/online tool). The data is extracted and final computations for equipment, labor; material etc. is carried out (Sylvester et al.). Current construction estimations practices are taking on-screen takeoffs directly which help us give an accurate answer. It helps to determine estimates part by part and also does not utilize excessive cross-checking time. Software, like Bluebeam, is used currently in the construction industry for the purposes of estimation. The different types of estimation techniques are:  Informal. Washington State Department of Transportation (WSDOT) sometimes uses informal cost-per-miles tables for estimating highway projects during planning stage (Turochy et al., 2001).  Historical. Historical Bid-Based Estimate can also be considered as unit cost estimate where the number of items or objectives to be finished is directly multiplied by their unit cost. This is the most common type of estimating at WSDOT (WSDOT working definition).  Special Cases. Resource Enumeration is required for special features of a project for which unit pricing is not available. Currently, most projects have special features,

31 machines or equipment to execute cost estimates when estimates using unit price is not available. Consequently, for such project features, historical data might be used or estimation intuition is required to calculate cost of such projects.  Risk-Based. Risk-Based Estimate involves probabilistic relationship between cost, schedule and other factors involving a project. The Base Cost of a project is calculated normally considering all aspects are normal; however, there is a scope of risk factors which are then included to provide an approximate range of cost and time (schedule) (WSDOT working definition). 3.7.3.4 Innovative Practices  Model-Based Estimating. Estimating is moving towards estimates based either partially or wholly based on three-dimensional digital model systems. Building Information Modeling (BIM) is the common term used to describe the digital representation of physical and functional characteristics of an infrastructure system (typically, but not exclusively used for buildings). BIM usually involves a three-dimensional (3D) model of the infrastructure subject and may include a time dimension (a 4th dimension that addresses schedule), and cost data (a 5th dimension). An automated quantity takeoff (QTO) can be done within the BIM environment by linking the 3D model with cost data. Benefits of model-based estimating are usually reported as efficiency, accuracy and cost savings. The traditional system for estimating consisted selection of individual members in CAD drawings and then listing it in QTO list. Later these were simulated in Excel for the final estimates. Thus, the generation of QTO list is time consuming and is based on manual operations which leads to errors (Xinan Jiang, 2011). Automating QTO. QTO automation can be done by three methods:  BIM tool exports quantities. BIM models can export quantities to common file types. For example, Autodesk Revit allows direct transfer of a bill of quantities into an Excel Spreadsheet.  BIM tool links directly to estimating software. This eliminates an intermediate file and provides increased function by directly linking BIM quantities with an estimate tool. Examples include Innovaya, Graphisoft Estimator, Success Estimator etc.  BIM QTO tool. The BIM tool contains an integrated QTO tool, which has the advantage of creating a specially designed tool for a particular project. This tool will help collect data regarding different specific and unique assemblies/items and create visual takeoffs diagrams. Software like Autodesk QTO, Exactal, Innovaya etc. are already being used by some contractors. Unmanned Aerial Vehicle (UAV). Some state departments of transportation (DOTs) are investing in innovative drone technology to improve safety, save money and reduce congestion (CTC and Associates, 2014). However, the UAVs can have a greater contribution towards estimation as well. The UAVs can capture aerial images suitable for traffic surveillance and data collection. Additionally, the drones are cheaper to fly than manned aircrafts and can collect data more efficiently than the naked human eye which provides more accurate results. With the help of computational tools and technological advances, sensor data can be converted into 3D

32 structural models, topographical maps and volumetric measurements. The UAVs are resourceful in conducting traffic surveys which helps analyze traffic systems in an upcoming project area. Overall, the automated data delivery provides will be increased accuracy, increased precision and more streamlined organization. Flores et al. (2012) describe a convertible mini-UAV which is currently under development for highway estimation and tracking. It uses the innovative technology of Switching Control strategy in cases where road is detected or it is not detected. In this system, the quad-plane mini unmanned aerial vehicle navigates autonomously and helps track movement, explore areas and keep traffic related data for roads and highways. Gebre-Egziabher (2011) developed a framework for design of concept of operations to support intelligence transport systems applications with help of UAV, where these vehicles are used to collect information about traffic and inspection of roads and bridges at remote locations. The risk and limitation to be managed here is vehicle infrastructure collision. One of the solutions to be relayed is a multisensor approach, which combines digital maps of the infrastructure being inspected with an integrated Global Positioning System. There has been research and vast usage of this technology for various purposes to include use of UAV as a hybrid micro aerial vehicle for ingress and egress of urban environments (Green 2009). Small bird-type air robots that can fly over obstacles and pass through small openings to assist in acquiring and distributing intelligence during reconnaissance, surveillance and search and rescue missions in urban settings; the author describes it to be holistic approach. Light Detection and Ranging (LIDAR). LIDAR is the process of scanning earth with lasers from an aircraft to obtain accurate elevations (Iowa LiDAR Project). Most common use of LIDAR is for geodesy, geomatics, archaeology, geography, geology, geomorphology, seismology, forestry, and atmospheric physics. But, with the growth of technology, LIDAR technology can be beneficial for roadway siting, planning and estimating as well as construction estimating. It can also help providing suitable plans for roadways, utility lines, pipelines etc. Krogstad et al (2004), proved how efficient LIDAR technology can be in the transportation section, particularly in areas covered by forests. Detailed LIDAR topography helps identify difficult stream crossings, unstable soil, and side slopes. These details help in developing better cost estimates. Paula Florina (2013), also provides evidence through research based on the increasing use of LIDAR for determining the forest parameters. The latest advancement is the mobile mapping with LIDAR technology. The laser scanner is mounted on a vehicle and it operates while the vehicle is in motion at the designated location. Thus, this technology can help a lot in surveying and creating efficient schedules which help produce a better cost estimate. This mobile mapping technique can provide sufficient data for 3D analysis and support the creation of designs as well as provide quantities. Mobile mapping is also useful in the as-built phase since it provides a complete 3D printout of the final project (Optech Lynx Application Note). The adaptability of this application made it significant in all phases of construction improving safety conditions and streamlining multiple tasks. In regard to roadway planning, this technology can accelerate the location process since it does not depend on the environmental conditions. Consequently, the use of this technology may result

33 in cost and time savings of at least 50 percent. Even though this technology may not completely replace photogrammetric data in the final design of alignment, it still yields significant value. High-Resolution Digital Elevation Model. Earthwork represents the major highway construction cost. Traditionally, earthwork volumes were estimated using the prismoidal method (Hickerson, 1964). This method has long provided a reasonable estimate for non-linear ground profiles. However, with the intervention of High-resolution Digital Elevation Models derived from LIDAR technology, the estimation of earthwork can become more precise and more efficient. Contreas et al. (2012) developed a computerized model to estimate earthwork volumes for low forest density roads using a high-resolution DEM. According to their work, the quantity estimate increases as the cross section spacing is reduced. The technology works in the following sequence:  Ground elevations for each survey station are obtained from the LIDAR-derived DEM.  Once the points are fixed, Location for horizontal curves are determined.  Once all the data points are set, individual segment length of the roads are calculated.  Cross section is determined location based and then it is designed accordingly.  Cut/fill areas are calculated and estimated automatically. The entire manual work gets transformed into computational algorithmic based mathematical function and is calculated much faster (Contreras et al., 2012). TABLE 12 captures a brief summary of the innovative practices identified, cost information was not available for most of the techniques. TABLE 12. Estimating Innovative Practices Summary Technique Relation to Sustainability BIM Reduce costs, saves time, Results more accurate and visual in some cases. UAV Less human errors, Cost-effective, still under research so wide scope for development. LIDAR Currently under research, effective 3D modeling with details resulting in most effective estimates, coupled with UAV it is cost saving and saves human resources as well. High-Resolution DEM Type of LIDAR giving fairly accurate estimate for earthwork or any cut/fill operation estimates. Cost reducing & time saving. 3.7.4 Project Controls 3.7.4.1 Definition  The performance of highway construction projects is largely dependent on the project management strategy and the ability to disseminate project status information to all stakeholders in a timely manner (Grau and Abbaszadegan, 2015). Project control is defined as a set of processes that ensure the timely delivery of a project that is within budget (Olawale and Sun, 2010). An effective and efficient project control system allows stakeholders to make informed decisions using the most current data available.

34 Project control systems are generally comprised of an information management system and personnel who collect and process information into the system (CII – RS6-5). The Construction Industry Institute (CII RS6-5) breaks down project control in the construction phase to cost control, schedule control, and material control. Cost control compares actual to budgeted expenditures to analyze cost overrun, underrun, and trends. Schedule control compares the current progress schedule to the baseline schedule to minimize or negate schedule deviations. Material control deals with tracking of permanent and temporary materials to ensure timely procurement and prevent schedule delays. These three project control elements are used to compare the actual project status to the baseline planned performance. 3.7.4.2 Relation to Sustainability   Dimension Category Indicator Environmental Wellbeing Natural Resources Consumption Economic Wellbeing Project Economy Cost-Benefit   Project control systems can impact environmental wellbeing and economic wellbeing. Electronic project control systems minimize or negate the need to track cost, schedule, and materials on paper forms or on field notebooks. Consumption of paper is minimized by tracking information in an electronic environment (Snow et al., 2013; Vaughan et al., 2013). A Peer Exchange workshop sponsored by the Federal Highway Administration (FHWA) held in Salem, Oregon in March 2015, revealed that Michigan Department of Transportation was able to reduce 6 million pieces of paper as well as reduce postage, envelopes, and storage space by implementing an electronic construction document management system across the entire agency. The agency estimates a saving of $12 million as a result of minimizing resource consumption. Regarding economic wellbeing, the project control method can have an influence on time savings, document and information dissemination, and the quality of information (Memon at al., 2005; Melville 2010; Snow et al., 2013; Valdes et al., 2013; Grau and Abbaszadegan, 2015; Yamaura et al., 2015; Omar & Nehdi 2016). These factors all contribute to the cost-benefit indicator. For example, implementing mobile devices with field inspection software allows inspectors to capture and share field data and reports in real time. Compared to project control methods based on a paper-pen method, mobile applications that allow inspectors to generate and submit field documentation directly from the field saves inspectors administrative time and effort as well as time savings from negating the need to travel back to the project office. 3.7.4.3 State‐of‐the‐Practice  Research into current project control methods yields various methods in collecting, documenting, and analyzing project controls information on construction projects. Recent studies show that much of the project controls data is captured using a paper-based method and later duplicated into an electronic documentation retention system (Alshawi and Ingirige, 2003; Boddy et al., 2007; Snow et al., 2013; Valdes et al., 2013; Yamaura et al., 2015; Bianchi et al., 2016). Washington State DOT (WSDOT) uses a similar method across the agency in collecting and storing project controls data (Yamaura and Katara, 2016). The following section describes WSDOT’s general project control method. In terms of cost control, WSDOT project engineering offices process field note records (FNR) to facilitate payment to the contractor. Figure 1 shows the workflow process involved in processing

35 an FNR. The initial process of the workflow involves field inspectors collecting project inspection observations to determine the following:  Basic contract and project information  Bid item number and the associated description and unit of measurement  Supporting calculations showing the arithmetic used to arrive at the final quantity value FIGURE 1. WSDOT field note record workflow process (Yamaura and Katara, 2016).FIGURE 1 shows considerable amounts of data related to quantity tracking and material verification that must be accessed to fill out the FNR form. Studies have found that inspectors are collecting inspection information, including quantity tracking and material verification, using a pen-and- paper method directly in the field (Valdes et al. 2013; Snow et al. 2013; Yamaura et al., 2015; Wang et al. 2016). The pen-and-paper data collection method is cumbersome as information already noted in the inspector’s notebook is duplicated into various documents such as the FNR. Snow et al. (2013) found that inspectors spend an average of 1.9 hours per shift entering project control information into the agency project control system in their computer. Figure 1 also shows inspectors need to access multiple agency database programs to populate fields in the FNR form. Furthermore, the information from the FNR is transposed into an agency payment database program, which manages the financial accounting of the project. The data collection method and database programs are not all integrated, requiring inspectors and other personnel involved in the cost control process to spend time on administrative tasks. FIGURE 2 provides a generalized workflow diagram of the entire project control process adopted by WSDOT. This diagram includes the cost control activities mentioned above, but also includes material and schedule control elements. Due to the complex workflow structure involved in maintaining project control information, supporting documentation may not be submitted in a timely manner. Grau & Abbaszadegan (2015) documented cases in which upper management made project decisions using six-month old information. The inability to collect timely project control information can lead to project managers reacting to issues rather than taking a proactive approach to deliver the project on time and in budget (Grau & Abbaszadegan 2015; Omar & Nehdi 2016).

36 FIGURE 1. WSDOT field note record workflow process (Yamaura and Katara, 2016).  FIGURE 2. WSDOT project control process (adapted from WSDOT NW Region Process Chart).

37 An effective project control method relies on the project stakeholder’s ability to obtain timely and accurate information in regard to project cost and schedule performance. Research in this field has led to advancements in information technology and project management strategies to improve the timeliness and accuracy of construction information dissemination (Grau and Abbaszadegan, 2015). For example, the FHWA has been promoting their e-Construction program, a program that provides funding and support to state DOTs to help achieve a paperless construction administration delivery process, through their Every Day Counts 3 initiative. FIGURE 3 shows the number of State DOT agencies that have initiated e-Construction practices to move away from their traditional paper-based project control documentation procedures. As of September 2016, all but three state DOTs have adopted e-Construction practices and about a fifth of all state DOTs have fully implemented this practice across their entire agency. FIGURE 3. Current status of e-Construction programs across state DOTs. (FHWA, 2016).  3.7.4.4 Innovative Practices  Recent literature has focused on adopting innovative data acquisition technologies to reduce the time taken to collect the information and to store all information in a centralized location. Omar and Nehdi (2016) classified data acquisition technologies into the following categories:  Enhanced IT technologies  Geospatial technologies  Imaging technologies

38 Enhanced Information Technology (IT). Enhanced IT include the adoption of multimedia tools, email services, voice-based tools, short message services (SMS), and handheld computing tools. These technologies improve stakeholder communication and improves the stakeholder’s ability to control project delays and cost overruns (Omar & Nehdi 2016). Handheld computing tools, such as tablet computers, stand out from the rest of the IT technologies as they have the capability to integrate multimedia tools, email services, voice-based tools, and short message services (Snow et al., 2013; Yamaura et al., 2015). Enhanced IT are generally pursued to reduce costs and increase available/accessible information. Inspectors working for DOTs that have adopted handheld computing tools paired with information management systems specifically developed to meet the agency’s business process have been able to incur average time savings of 1.76 hours per shift per inspector (Yamaura et al., 2015). The time savings can be converted to overall productivity increase, which can then be used to calculate an approximate workforce multiplier to the inspection workforce. FIGURE 4 shows the workforce multiplier findings from three DOT case studies. The outcome of improved inspector productivity can be seen as an increase in the capacity of DOT workforces without requiring additional staff. TxDOT’s workforce of 1,092 inspectors can perform like a workforce of 1,350 inspectors, effectively increasing their capacity by 258 inspectors. FIGURE 4. Increase in equivalent workforce resulting from the use of mobile technology (each person represents 25 inspectors), (Yamaura et al., 2015). Geospatial technologies. Geospatial technologies help site managers track actual conditions of on-site construction objects (Omar & Nehdi 2016). Specific geospatial technologies include barcoding, radio frequency identification (RFID), ultra-wide band (UWB), geographic information systems (GIS), and global positioning systems (GPS). Omar and Nehdi (2016)

39 concluded that geospatial technologies are suitable for tracking material location in real time. 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 mixes (Schwartz et al., 2014). Vehicles outfitted with a bumper-mounted antenna array was able to reliably read the RFID tags moving at free-flow speeds. RFID technology has also been applied to track individual pipe spools to reduce the time it takes to locate the material and reduce the number of misplaced pipes (Song et al., 2006). In terms of sustainability, adopting geospatial technologies impact the economic wellbeing dimension, with cost reduction and increased benefit as the indicator. Time and effort in tracking construction objects is reduced by using geospatial technologies. Imaging technologies. Image-based modeling and 3D laser scanning (LIDAR) are some common used imaging technologies currently available in the industry (Alizadehsalehi and Yitmen, 2016; Omar and Nehdi, 2016). Literature on construction progress tracking using image-based modeling has been investigating methods to compare digital images to 3D CAD models in a common coordinate system (Alizadehsalehi and Yitmen, 2016). Digital images captured on-site are converted to 3D CAD models using photogrammetry techniques. The actual site conditions modeled in 3D CAD can be compared to the baseline 3D CAD model to determine the progress of specific work activities and percent completion of the project (Memon at al., 2005). Golparvar-Fard et al. (2009) developed a method of visually depicting project progress and deviations by overlaying an as-planned 4D model on time-lapsed site progress photographs. This resulted in relatively new way to visualize project progress reports compared to traditional text-based progress reports as shown in FIGURE 5 (Golparvar-Fard et al., 2009). 3D laser scanning technology has also been used to generate 3D models of as-built conditions. This method uses a laser scanner to gather distance measurements of surfaces around the device. Building information modeling (BIM) software can be used to convert these point cloud datasets to a 3D CAD model. Similar to the photogrammetry method above, LIDAR generated as-built models are compared to the baseline 3D CAD model to track materials and schedule components of the project (Xiong at al., 2013; Omar and Nehdi, 2016). Although the initial investment cost of these imaging technologies can be costly, integrating the information into the project control system allows personnel to quickly compare as-built conditions to baseline estimates, revealing material and schedule progress. Adopting imaging technologies improve the economic wellbeing of the project by providing the benefit of increased accuracy of the quantities tracked with in the project.

40 FIGURE 5. Visualized monitoring report (Golparvar-Fard et al., 2009). 3.7.5 Contract Administration 3.7.5.1 Definition  The concept of Value Engineering was developed during the Second World War to identify innovative construction practices that could potentially lead to cost savings. Design-Bid-Build project delivery methods are usually used in value engineering studies as they allow the early involvement of construction contractors (Halpin and Senior, 2012). 3.7.5.2 Relationship to Sustainability  Dimension Category Indicator Economic Wellbeing Project Economy Cost-Benefit

41 3.7.5.3 Innovative Practices  Studies by M. A. Beheiry, Kiong Chong, and T. Haas (2006), Hassan et al. (2016), Valdes- Vasquez & Klotz (2013) have addressed the social aspects of sustainability. 1. M. A. Beheiry, Kiong Chong, and T. Haas (2006) developed two indices namely, Corporate Sustainability Commitment Index (CSCI) and Sustainability Component of Project Planning index (SCPPI) to measure the change in project performance due to involvement of owners. They found that increased involvement improves sustainability outcomes as project participants become more aware of the goals. 2. Hassan et al. (2016) developed a model that determines the change in the level of sustainability with a change in the behavioral attributes of an organization. The results indicated six variables that had significant impact namely, country of the firm, the size of projects, publicity value of the project, the probability of taking aggressive risks, the status of modulus operand and low-price competitiveness of the firm. 3. Valdes-Vasquez & Klotz (2013) developed a framework to include social considerations in construction projects by dividing social sustainability into four concepts namely, community involvement, corporate social responsibility, safety through design and social design. The following are relevant examples from case studies in the INVEST program. 1. Western Federal Lands, during the rehabilitation of the Sun Road between Big Bend and Logan pass (Sustainablehighways.org, 2017), implemented safety measures near the rock fall locations as a part of a mitigation program using Intelligent Transportation System (ITS) to provide the traveler actual information about road condition, parking availability and others for the. 2. Utah DOT has saved about $3M by incorporating ITS in traffic signal operations and using innovative technologies like dynamic dilemma zone and corridor responsive ramp metering. Additionally, the study resulted in improved air quality, reduction in user delay and reduction in fossil fuel usage (Sustainablehighways.org, 2017). 3. Springfield Sangamon County Regional Planning Commission (SSPRC) constructed pedestrian access to improve safety during the construction of the Historic Route 66 Corridor Project. Additionally, the study aimed at preventing the historical, archeological and cultural heritage of the surrounding area (Sustainablehighways.org, 2017). 4. Arizona DOT used context-sensitive approach to increase the safety of people and maintain aesthetic of the surrounding environment during the construction of SR-179 in Sedona (Sustainablehighways.org, 2017). 5. Central Federal Lands involved the employment of environmental compliance monitor by the contractor for resource monitoring during the construction of Halstead Meadow Bridge in Sequoia. Additionally, the installation of bridge facilitated natural flow of water and provided safe passage for wildlife to pass safely underneath the bridge (Sustainablehighways.org 2017). 6. Eastern Federal Lands constructed pedestrian and bicycle access and tried to maintain the ecological connectivity during the construction of Mulligan Road in Fairfax County (Sustainablehighways.org 2017). Illinois Tollway concentrated on increasing the biodiversity and tried to protect the stands of trees (Sustainablehighways.org, 2017).

42 7. Western Federal Lands diverted about 75% of the construction waste using formal construction and waste demolition plan from going into the landfill for the North Park Road (Sustainablehighways.org, 2017). 8. Arizona DOT reduced the distance traveled by trucks to haul the wastes by proper planning with the contractors for the roundabout project. Additionally, the project planned for managing the waste streams generated due to the construction activities while documenting the scope of the project itself (Sustainablehighways.org, 2017). 9. Western Federal Lands kept track of the wastes generated due to the construction activities and tried to divert them for the construction of Forest Highway 26 (Sustainablehighways.org, 2017). 10. Ohio DOT prevented about 0.1 million cubic yards of waste from entering the landfill during the construction of Cleveland Inner belt George Voinovich Bridge (Sustainablehighways.org, 2017).  3.7.6 Earthwork 3.7.6.1 Definition  Sustainability can be achieved in construction earthwork by balancing the amount of cut and fill in order to minimize the amount of earthwork. Further, optimization of earthwork operations can reduce the cost and the environmental impacts associated with the use of equipment. 3.7.6.2 Relationship to Sustainability  Dimension Category Indicator Environmental Wellbeing Nature & Environment Ecological Resources   3.7.6.3 Innovative Practices  Following are some examples of sustainable construction practices in earthwork operations: 1. Goktepe & Lav (2003) balanced the amount of cut and fill for a pavement section 100m long, and 20m wide with the help of weighted ground elevation method. 2. Arizona DOT balanced the cut and fill for rural construction projects to reduce truck haul distances during the construction (Sustainablehighways.org 2017). 3. Bogenberger et al. (2015) developed a two-phase model to optimize the earthwork activity for highway construction. The first phase of the model dealt with the problem to optimize the overall flow of materials described by the schedule while the second phase involved a disaggregated model to determine the actual flow of the materials. 4. Kim & Chen (2015) proposed a data integration method using Building Information Model (BIM) and Geographical Information Systems (GIS) to reduce earthwork. 5. Hyeok Kang, Won Seo and Geun Baik (2009) developed a method using a GIS-based planning system to conduct internal/external earthwork planning considering 3-D topographic conditions of the construction site and surroundings. 6. Duffell and Rudrum (2005) obtained savings in whole life cycle costs by using remote sensing technologies such as satellite photography, vertical aerial photography, oblique photography, and airborne videography, LiDAR, thermal line scanning, vehicle videography and the advantages associated with them.

43 Each of these methods led to cost savings, and improved environmental outcomes through lower use of equipment resources. 3.7.7 Drainage/Sewer/Water 3.7.7.1 Definition  The main objective of the drainage design during highway construction is to reduce or eliminate the energy generated by flowing water. The engineering properties of materials used for highway construction highly depends upon the quantity of moisture present in the subgrade under the highway (FAO UN, 1989). 3.7.7.2 Relationship to Sustainability  Dimension Category Indicator Environmental Wellbeing Nature & Environment Clean Water Water Resources 3.7.7.3 Innovative Practices  Water main replacements often coincide with highway construction making them relevant to this study. Koo & Ariaratnam (2008) assessed the use of three alternative pipe placement methods namely, ductile iron pipe using conventional open cut with shield, high-density polyethylene pipe using pipe bursting method, and fusible polyvinyl chloride pipe using horizontal directional drilling method, and reported that the pipe bursting method releases the least amount of NOx, SOx and CO2 as compared to the other two alternatives. In addition, Koo et al. (2013) suggested the use of trenchless technologies as they result in fewer disruptions, reduce carbon footprint and extend the service life of existing structures. The studies carried out by Y. G. Andoh and O. Iwugo (2004), Wolf et al. (2015) show the advantages of using sustainable urban drainage systems. Y. G. Andoh and O. Iwugo (2004) indicate that use technologies such as hydrodynamic vortex separators, geo-plastic storage systems, and vortex flow controls are more effective. Wolf et al. (2015) reveal that ponds constituted highest whole life cycle costs and detention basins constituted lowest whole life cycle costs for a pavement of life 50 years. 3.7.8 Structures: Aesthetics 3.7.8.1 Definition  The term aesthetics broadly addresses the philosophical theory or set of principles governing the idea of beauty at a particular time and place. Perhaps more eloquently stated as “…having to do with the beautiful as distinguished from the useful, scientific, or moral.” (Burke 2004). For this review, specifically focused on highway construction, “construction aesthetics” more narrowly addresses e quality of (1) temporary construction facilities (e.g., fencing, offices, equipment), and (2) permanent infrastructure where construction actions can affect such qualities (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.

44 3.7.8.2 Relationship to Sustainability  Dimension Category Indicator Human Wellbeing Health & Happiness Culture and History Aesthetics   Humans place value on what they can see and its quality so the aesthetics of a particular community or location contribute to the human wellbeing component of sustainability. This is both through pure visual pleasure and how aesthetics represents the culture and history of the community. Evidence suggests that aesthetics produce measurable physical and psychological benefits (e.g., Gallioano & Loeffler, 2000 cite Driver, Brown, & Peterson, 1992; Urich, 1984) and that those benefits can be measured (usually via economic worth), although usually not directly (e.g., Bastian, McLeod, Germino, Reiners, & Blasko, 2002; Jarves, 1879; Jim & Chen, 2009; Lange & Schaeffer, 2001). Therefore, aesthetics have long been integral to infrastructure development (Schutt, Phillips, & Landphair, 2001). Examples can be readily seen in bridge design (e.g., Zuk, 1995; Burke, 2004; Sobrino, 2013), master plans for highway corridor aesthetics (e.g., (Sipes & Blakemore, 2007; Nevada Department of Transportation, 2002), as well as the inclusion of aesthetics in Environmental Impact Statements. 3.7.8.3 State‐of‐the‐Practice  Aesthetics are typically an overt consideration for major highway projects (e.g., Meyers, 2004; Parametrix, 2009; Pielstick, 2000; Sipes & Blakemore, 2007; Whitney & Chung, 2004), but are usually addressed only by standard policy or practice for more routine work such as paving and maintenance. Organizations usually have written guidance on landscape design (Schutt et al., 2001), and sometimes provide additional guidance or policy on the appearance of structures (e.g., Caltrans, 2014; Nevada Department of Transportation, 2002). Consideration for aesthetics is usually at the design level, with minimal freedom given to choose aesthetics during the construction process itself. Almost nothing is written about the aesthetics of active construction sites themselves, however lighted tower cranes, flags mounted on derrick cranes, and creative fencing aesthetics suggest that owners and contractors alike find value in such things (FIGURE 6, FIGURE 7).   FIGURE 6. Construction fencing aesthetic treatment on the University of Washington campus. Photo credit: S. Muench, used with permission.   

45 FIGURE 7. American flag on an asphalt paver, an example of construction site aesthetics. Photo credit: S. Muench, used with permission.  Specific aesthetic treatments that are at least partially determine during construction are typically wall or bridge abutment treatments (e.g., the contractor is responsible for meeting aesthetic intent expressed in design by procuring appropriate concrete form liners), temporary erosion control, clearing practices, borrow pit operation, clean up, waste areas, and general construction site aesthetics in the form of fencing design, lighting, flags, and other features (Federal Highway Adminisration, 1988). Issues with aesthetics typically involve achieving a good combination of aesthetic value and construction economy, as well as the aesthetic impacts of a messy or poorly maintained construction site. 3.7.8.4 Innovative Practices  The literature tends to focus on (1) theoretical discussions on the value of aesthetics, (2) aesthetics assessment, and (3) economical and practical inclusion of aesthetics in infrastructure. This section focuses on the third item. Economical Aesthetic Wall Design. Some owners and trade organizations provide guidance on how to create desirable aesthetics in an economical manner. Caltrans has an extensive guide on aesthetic wall treatments (Caltrans, 2014) 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 all the contractor latitude to select aesthetics within some sort of bounds. FIGURE 8 provides an example of an aesthetic wall treatment. Aesthetics recommendations from Caltrans (2014) include:  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.

46  Align expansion and weakened plane joints with footing step locations.  Wall footing step heights must be in 1, 2, or 4-foot increments to facilitate gang form system construction and provide for the alignment of horizontal seams.  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 liner because they provide for multiple uses and produce high- quality textures and patterns.  Aesthetic textures and patterns should extend outward from the structural wall section, adding thickness to the outer face of the wall.  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 established 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 advertisement for bid, when available.  Require the contractor to construct test panels that demonstrate the wall aesthetic treatments required by the project.  The landscape architect and/or Structures architect provides on-site support to the RE (resident engineer) as necessary to ensure the aesthetic design intent for the wall structure is not compromised in construction.

47 FIGURE 8. Aesthetic wall treatment on I-5 in Tacoma, WA. Photo credit: S. Muench, used with permission. Costs associated with form liners vary depending upon the type of liner used. Single-use plastic liner may be as low as $2-3/ft2, while urethane liners may cost upwards of $20-30/ft2 but can be reused about 100 times or more. Both can generally be recycled. Single-use liners are more popular for projects with small or irregular areas of aesthetic treatment (e.g., bridge abutments) while urethane liners are more common for large, repeating areas (e.g., sound walls). Context-Sensitive Rock Slopes. The FHWA Federal Lands Highway Division has written on (Andrew, Bartingale, & Hume, 2011) and extensively uses what they call “context-sensitive rock slope design,” that is, rock slopes constructed so as the be consistent with the project’s surroundings, either natural environment or historical setting and community (FIGURE 9). 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). The Federal Lands Highway Division describes the entire process of rock slope design and construction including the design process, rock excavation methods, rock slope/landscape integration, rock slope stabilization, rock fall protection, and rockfall mitigation. Importantly, it describes a method to integrate these ideas to arrive at an aesthetically pleasing rock slope that provides slope stabilization and rockfall protection.

48 FIGURE 9. Forming a natural-looking rock slope near Fernan Lake, Idaho on a Federal Lands Highway project. Photo credit: C. Croft, University of Washington, used with permission. Construction site aesthetics. Almost no literature exists on the benefits, costs or practices of construction site aesthetics (i.e., related to temporary fences, temporary erosion control, lighted or decorated cranes/derricks, etc.), however they are frequently specified or undertaken by the contractor at their own expense. 3.7.9 Structures: Bridges 3.7.9.1 Definition  Sustainability in bridge construction is discussed by addressing different and new construction methods that can be implemented. The three main categories described are Accelerated Bridge Construction, Sustainable Bridge Deconstruction, and Duplex Stainless Steel Bridges. The document describes the benefits of these methods and introduce new and innovative solutions for more sustainable construction. 3.7.9.2 Relationship to Sustainability  Dimension Category Indicator Human Wellbeing Health & Happiness Aesthetics Economic Wellbeing Project Economy Cost-Benefit

49 Sustainability in bridge construction is measured by three dimensions; economic, environmental, and human dimensions. Through the research work, it was found that sustainability in bridge construction is mainly related to cost-benefit indicator in the economic dimension, consumption in the environmental dimension, and safety and aesthetics in the human dimension. 3.7.9.3 Innovative Practices  Accelerated Bridge Construction (ABC). ABC uses safe and cost-effective planning, design, materials, and construction methods to reduce the on-site construction time for new bridges or replacing and rehabilitating existing bridges. They include many erecting techniques. The primary benefits of ABC are:  Human safety is enhanced for the motorists and the construction crews.  Reduce construction footprint to preserve habitat and reduce environmental impact.  Some ABC methods leads to lower cost which increases contractor economic benefit. The methods discussed in this section are: 1. Prefabricated bridge elements and systems (PBES) 2. Geo-synthetic reinforced soil-integrated bridge systems (GRS-IBS) 3. Slide-in bridge construction 4. Incremental Launching Method (ILM) Prefabricated Bridge Elements and Systems (PBES). PBES includes off-site prefabrication of construction elements which offers significant social, environmental and economic benefits. The benefits of PBES is that it reduces energy consumption as the mobility of materials is reduced. They lower projects costs by eliminating the need for temporary bridges, reducing utility relocations, and decreasing the total project delivery time. They ensure safety by using fewer on-site activities, and reduce site impact. Contractors tend to consider steel bridge prefabrication with higher costs than cast-in-place bridge construction. They expense the cost of the equipment over one project instead of multiple projects. However, costs can be lowered by standardizing prefabricated bridge construction. For structural steel rolled shapes and fabricated plate girders the welding is preferred to be in the fabricating plant, so prefabricating the bridge offsite offers better quality in this case. Welding at site is not preferred because of the environmental control that makes it difficult to produce acceptable weld quality. (Steel et al., 2017) Geo-synthetic reinforced soil-integrated bridge systems (GRS-IBS). The method uses alternating layers of compacted granular fill material and geo-synthetic reinforcement to provide support to bridges. The GRS-IBS abutments are easier to build and are 25 to 60 percent more cost-effective than conventional. 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

50 piling activities. In addition, the system is easy to design and can be built in variable weather conditions. The system significant advantages appear in small, single span structures (Adams, 2010). Slide-in bridge construction In SIBC, the traffic is unaffected on the existing bridge, while the new bridge is built on temporary supports, usually parallel to the existing bridge. The road is then closed when the bridge is constructed and the existing bridge is demolished. Then, the existing bridge is slid in place, tied into the approaches, and paved generally within 72 hours. Benefits of SIBC:  Less Traffic disruption.  Shortened work zone durations so there is greater safety for motorists and construction workers.  Greater quality and constructability.  Reduced vehicle and construction equipment emissions. Incremental Launching Method (ILM). In incremental Launching, the bridge is assembled in one side then is pushed (launched) into its final position in a series of increments. Although ILM is not the most economical solution for bridge construction and requires a considerable amount of analysis and specialized construction equipment, it has other benefits. It creates habitat conservation as it has minimal disturbance to the surrounding environmental areas. It ensures higher safety for workers as all the erection work is performed at a lower elevation. It also requires smaller and concentrated area for superstructure assembly, so it can be used to construct bridges in challenging sites with restricted access (Laviolette et al., 2007). Segmental Concrete Bridge Construction. Segmental concrete bridges are very economical. There are multiple methods that can be implemented in segmental construction, and this gives contractors the ability to tailor each project to their available equipment. Thus, it optimizes cost and maximizes efficiency (Barker, 1980). Another benefit that maximizes profit is that the fabrication of the segments can be done while the substructure is under construction. In addition, the segmental concrete bridges use pre-stressed precasting. This eliminates the time for the concrete strength gain in the project critical path. This decreases the construction time for the contractor. The building bridges in segments ensures quality control, as the precast concrete is produced in factories. The effects of creep and shrinkage are minimized as the concrete matures at the time of erection in factories (Park & Ward, 1950). Sustainable Duplex Stainless Steel Bridges. Duplex stainless steel has two main elements: Austenite and Ferrite. Duplex produces chemical composition that has approximately the same mixture of Ferrite and Austenite. This leads to many performance benefits which include higher strength, good weldability, good toughness, and high resistance to stress corrosion cracking. Other advantages of duplex stainless steel include higher strength leading to weight saving, better price stability, and being cheaper. It is lighter so less production is needed. It allows lightweight construction which gives us the chance to build larger spans and reduce the number of supports for bridges which reduces the need for hazardous work environment.

51 It is worth to mention that the production of mass of stainless steel have higher CO2 emissions and energy consumption than carbon steels. However, this is compensated by the fact that less duplex stainless steel production is needed than carbon steels. Stainless Steel is 100% recyclable without any loss in performance. Lighter construction reduces construction time, foundations, and ground disturbance. The initial costs and factory production of duplex stainless steel bridges is higher, but the cost/energy use over the structure lifetime is more useful. The duplex stainless steel bridges can be more efficient if the cost of construction, operation, maintenance, and deconstruction is taken into consideration. The duplex stainless steel bridges have social benefits. It can be partially constructed offsite then assembled on-site. This reduces disruption to bridge users and hazards for workers. It also does not require intensive maintenance which increases safety and health. In the end, the stainless steel can be used to make complex geometries to achieve aesthetic aspects of the bridge, which lead to better appearance of the bridge (Baddoo & Kosmač, n.d.).  3.7.10 Structures: Walls Minimal to no literature to review. 3.7.11 Pavement 3.7.11.1 Definition  This section provides a brief overview of the sustainable highway construction concepts addressed in the FHWA’s Towards Sustainable Pavement Systems: a Reference Document (Van Dam et al., 2015). This section will concentrate on construction topics and will not include the planning, design, and operations and maintenance phases of a pavement life cycle. For the purposes of this investigation, pavement construction includes roadways and highways built above the natural soil. Sustainable highway practices will be considered within the context of “semi-permanent surface” construction. Semi-permanent roadway and highway construction contains two broad categories, asphalt concrete (AC) and hydraulic cement concrete (HCC). Asphalt can be produced using hot mix asphalt (HMA) and warm mix asphalt (WMA) whereas concrete systems can also include portland cement concrete (PCC). 3.7.11.2 Relationship to Sustainability  Dimension Category Indicator Environmental Wellbeing Natural Resources Consumption Economic Wellbeing Project Economy Cost-Benefit According to the American Society of Civil Engineers (ASCE, 2013), the U.S. invests about $90 million per year on road construction projects. The U.S. constructed or repaired nearly 960 thousand miles of asphalt and concrete in 2014 (FHWA, 2014). FIGURE 10 captures the transportation sector’s significant contribution to the total U.S. GHG emissions which totals 26% (Environmental Protection Agency (EPA), 2017).

52 FIGURE 10. Total U.S. Greenhouse Gas Emissions by Economic Sector (EPA, 2017). Generally speaking, the sustainability impacts of construction can be summarized in three strategic action items: (1) permit the implementation of sustainability best practices, (2) decrease unwanted environmental outputs of construction efforts to include fuel use, energy consumption and GHG emissions and (3) increase construction performance (Muench and Van Dam, 2014). These strategies will be addressed in more detail in the following sections by capturing best practices identified. 3.7.11.3 State‐of‐the‐Practice  Current practices within pavement construction projects have driven a need to focus on the recognition of five major influencing factors that contribute to the sustainability status of the project. The effects of pavement production, hauling, paving and compaction create concerns in five major categories including fuel consumption, emissions, traffic considerations (delay, noise and emissions), pavement surface considerations (safety, noise and fuel efficiency) and pavement life cycle performance. These five categories are the derivative consequences of the current practices within AC and HCC pavement construction operations.  Fuel Consumption. Fuel and energy consumption during a project is driven by all of the heavy equipment used during the construction operations (e.g. dump trucks, paving machines, compactors, etc.) and the accompanying effectiveness of the equipment. Aside from equipment effectiveness, haul distances, material and vehicle staging and the on-site traffic plan also influence the project’s fuel and energy consumption.  Emissions. As noted above, highway construction fuel consumption is a significant contributor to GHG emissions, mainly driven by the abundant use of heavy equipment with potentially long haul distances to transport construction materials. In fact, according to the EPA, highway construction emissions are the largest producer of emissions in comparison to all subcategories within the construction industry.  Traffic Considerations. The abundance of heavy equipment employed produces a significant level of unwanted noise, especially to neighboring occupants. Additionally, highway construction operations generate traffic delays and decrease access to local points of interest (2015). Consequently, road user costs typically increase as a result of

53 the prolonged time on the road and increase in fuel costs. In many cases, traffic diversions drive decreased revenue for local businesses impacted by the construction.  Pavement Surface Considerations. Low quality pavement construction can drive unwanted outcomes after the road has been opened to the public such as increased noise, reduced surface friction and reduced fuel economy.  Pavement Life Cycle Performance. Substandard construction execution will likely produce low quality pavement thereby decreasing the pavement’s life expectancy and simultaneously increasing sustainment costs. 3.7.11.4 Innovative Practices  Strategically speaking, the four major pavement construction best practices identified by the FHWA include the following (Muench and Van Dam, 2014):  Develop and implement specifications that promote sustainable best practices. Construction specifications require a need to be reviewed and adjusted to alleviate obstacles to sustainable practices.  Minimize unwanted environmental and financial impacts. Effective implementation of sustainable practices reduces fuel use, GHG emissions, secondary impacts to local businesses and local residents.  Streamline and strengthen effectiveness of construction tasks. The goal of this practice is to adjust the execution of construction tasks so that environmental and financial impacts are minimized while sustaining or improving the performance of the construction activities.  Increase construction quality. A higher quality construction output has many positive impacts to include longer pavement life, reduced sustainment costs and increased rider enjoyment. To break this discussion down further, the following subsections will briefly consider sustainable best practices within asphalt and concrete aspects of pavement projects. The costs, benefits and impacts of the strategies below are largely subjective and the predicted outcomes have limited data supporting the conclusions. Asphalt. Construction during asphalt pavement portions of a project offers opportunities to apply sustainable concepts. The FHWA’s Towards Sustainable Pavement Systems document identifies four major objectives with accompanying tactical recommendations to pursue and support sustainable endeavors. These include attaining specific densities, eliminating segregation, building proper longitudinal joints and attaining specific smoothness requirements.  Pavement density. Regarding asphalt pavement density, some of the recommendations include establishing a thickness large enough to accommodate the “nominal maximum aggregate size ratio” and employing “warm mix technologies”. Environmentally, the techniques will have significant benefits such as lowering the number of hauling trips, increasing crack resistance and the pavement life expectancy as well as decreasing the compaction temperature. Economically, the aggregate size tactic will likely reduce the number of lifts thereby reducing cost, but the warm mix techniques will increase costs as a result of additives required.  Segregation elimination. In order to eliminate segregation, a couple of the recommended strategies include employing material transfer vehicles and effectively

54 control and apply materials during the pavement construction sequence. These recommendations will environmentally enhance the project by lengthening the pavement’s life span and ensuring employment of effective material placement. Conversely, material transfer vehicles will increase costs of operations.  Build proper longitudinal joints. Effective sustainable strategies to construct proper longitudinal joints include application of sealants “overbanding” joints and sufficient compaction in support of effective joint density. As a result of these strategies, the life span of the pavement will increase and environmental impacts will be minimized through the use of sustainable materials.  Smoothness requirements. Lastly, achieving optimal smoothness can be attained through effective compaction techniques. Benefits of this recommendation include a longer pavement life span and increased fuel efficiency for vehicles traveling over the constructed pavement. Concrete. Construction of concrete pavements offers various opportunities to complete practically sustainable highway construction projects. Six sustainable objectives with accompanying recommendations are identified by the FHWA’s Towards Sustainable Pavement Systems. These include safeguarding water, decreased application of “virgin materials,” enhance “initial ride quality,” lengthen the pavement’s life expectancy, optimize “surface friction” with “tire pavement noise” and reduce fuel and emissions.  Safeguard water. In an effort to reduce water usage during concrete pavement operations, the recommendation is to contain and reuse water from concrete washes. Although this strategy will produce an added cost to contain and recycle the water, environmental impacts will be reduced by minimizing concrete water impact to the surrounding soils.  Decreased application of virgin materials. Regarding the decreased use of virgin material, the recommended practices are to initiate recycling on the project site and conduct two-lift paving. Economically, the recycling will reduce material and haul costs while the two-lift paving will increase costs. Environmentally, both tactics will reduce resource consumption and GHG production.  Enhance initial ride quality. Two-lift paving is a recommended sustainable strategy to enhance the initial ride quality. The outcome of this will have minimal economic impacts but will optimize the use of recycled material and reduce GHG production.  Lengthen pavement life expectancy. The implementation of effective quality assurance and effective curing methods are recommended sustainable techniques to lengthen the pavement’s life expectancy. Clearly, the major benefit to these tactics is a longer life cycle.  Optimize surface friction with tire pavement noise. The suggested approach to optimizing friction and noise is to select and install the most effective surface texture. Economic costs for this suggestion should be minimal but the major advantage is the potential to reduce pavement noise.  Reduce fuel and emissions. Lastly, a couple of the sustainable methods recommended to decrease fuel and emissions were to conduct one-lift compactions and to install roller- compacted concrete. Both recommendations listed above reduce costs, fuel use and GHG emissions.

55 3.7.12 Work Zone Traffic Control 3.7.12.1 Definition  “Work zone traffic control” refers to the temporary procedure enacted in a work zone in order to ensure continuity of movement of motor vehicles, bicycles, and pedestrians. It must also account for safety of workers and drivers, as well as accommodate efficient construction and resolution of traffic incidents. The FHWA’s Manual on Traffic Control Plans (2009) states that temporary traffic control is needed any time the normal function of a roadway is suspended. A work zone is defined by the MUTCD (2009) as “an area of a highway with construction, maintenance, or utility work activities. A work zone is typically marked by signs, channelizing devices, barriers, pavement markings, and/or work vehicles. It extends from the first warning sign or high-intensity rotating, flashing, oscillating, or strobe lights on a vehicle to the END ROAD WORK sign or the last temporary traffic control device.” 3.7.12.2 Relationship to Sustainability  Dimension Category Indicator Human Wellbeing Health & Happiness Healthy Life Safety Environmental Wellbeing Nature & Environment Natural Resources Clean Air Consumption Human Wellbeing. Effective work zone traffic control plans prevent traffic accidents so traffic control plans contribute to the safety aspect of sustainability. This is of concern to both the drivers going through the work zone and the workers themselves. In 2014, there were 669 fatalities in work zones (FHWA.org). Additionally, in a work zone fatal and injury crashes increase by 33% and property damage only crashes increase by 66% (La Torre, Domenichini, Nocentini, 2016). The traffic delays caused by work zones also affect the healthy lives aspect. Drivers in highly congested situations experience high levels of stress including frustration, irritation and negative moods (Hennessay and Wiesenthal, 1997). Inducing stress in drivers detracts from a healthy lifestyle and TCPs aim to reduce this effect though reducing congestion. Environmental Wellbeing. Effective work zone traffic control plans reduce congestion as much as possible, which helps reduce emissions and fuel consumption, and thus the surrounding air quality. Congestion affects emissions through periods of idling and crawling, and many accelerating and decelerating events (Zhang, Batterman, Dion, 2011). 3.7.13 State-of-the-Practice Work zone traffic control in the U.S. follows Part Six of the Manual for Uniform Traffic Control Devices (FHWA, 2012). Local jurisdictions may have their own traffic control manual but it must fully comply with the MUTCD. The major components of work zone traffic control address (1) continuity of movement, often measured by capacity in relation to demand, (2) safety of vehicles, bicycles, and pedestrians approaching and within the work zone, and (3) safety of work zone. Typical strategies employed to address these components are speed reductions, lane/road closures, active traffic control (e.g., pilot cars, flaggers), allowable/preferred times for work zones, information/warning/directive signs (e.g., signs, variable message boards), channelization

56 devices, and crash mitigation devices (e.g., crash cushions). Work zone traffic control research tends to focus on ways to implement these strategies and measures of their effectiveness. 3.7.13.1 Innovative Practices  Early Merge Control. When lanes are closed due to construction, some drivers will leave merging until the last minute, which can cause aggression and hostility between drivers. A research group in Michigan attempted to mitigate this effect using extra signage in the advance warning area of an active work zone traffic control plan. They added dynamic “Do not Pass/When Flashing” sings trailers which had sensors to detect speed volume and lane occupancy. The results of this experiment were that traffic crashes were reduced in the critical lane merge area, and that traffic delays were reduced (Datta, 2004). The research group also determined that this traffic control system should only be installed if it will be operational during higher volume periods of a lane closure, and it is on a highway that experiences moderate traffic prior to construction (Datta, 2004). Late Merge Control. Also known as the zipper method, this strategy makes use of the full capacity of the roadway and is thus applicable in high capacity situations. It can also be used when the length of the queue is of concern. Drivers are advised to use all lanes and later informed to ‘take turns’ at the merge point (Kurker et al., 2013). Signalized Merge Control. Intended to handle higher capacities than either early or late merge, signalized merge control tests have only been performed in simulation. When the signal is activated, it will alternately allow cars from each lane to pass, and has been noted to work well with cycles of 60 or 120 seconds (Kurker et al., 2013). Speed Management. Another issue which contributes greatly to safety hazards in work zones is speed of drivers. As stated in the MUTCD (2012), drivers will not reduce their speed unless they perceive a need to do so even when there is a lower speed limit in effect due to construction. NCHRP’s Synthesis of Highway Practices 482 (Shaw et al., 2015) describes a few case studies which try to replicate the enforcement effectiveness of a uniformed police officer in a more cost- effective manner. Below are strategies found to be effective.  Portable Changeable Message Sign with radar feedback sings and regulatory speed limit signs  Portable Changeable Message Sign with Radar Speed Feedback Sign  Speed feedback trailer with passive law enforcement  Automated Speed Enforcement  Radar Speed Feedback Signs

57 3.7.14 Materials 3.7.14.1 Definition  Naturally occurring materials such as clay, rock, and wood are used for construction activities. Apart from these, man-made materials such as asphalt, concrete and steel are commonly used in highway construction. As the review focuses primarily on highway construction, sustainable practices associated with the use of asphalt and concrete are discussed in detail and a few studies dealing with steel, wood, and rock are also included. 3.7.14.2 Relationship to Sustainability  Dimension Category Indicator Environmental Wellbeing Natural Resources Consumption Economic Wellbeing Project Economy Cost-Benefit The section highlights some of the main advances in the field of pavement materials that help in achieving highway construction sustainability. Cass et al. (2011) determined the environmental impacts from various phases of highway construction. The results of the study reveal that the production of the materials, equipment, and fuel used directly contribute to environmental impacts of the pavement. In addition, the material specific technologies used in pavement design and construction may also directly impact the performance of the pavement during its use. Hence, understanding the impacts of construction materials like asphalt, concrete, steel, wood, and aggregate are relevant to constructing sustainable highways. A complete survey of improving the sustainability of highway construction materials, as assessed using methods in Life Cycle Assessment can be found in the FHWA Sustainable Pavements Reference Document (J. Van Dam et al., 2015). 3.7.14.3 Innovative Practices  Asphalt materials. Asphalt has been used widely in the field of pavement construction. Perpetual pavements contain asphalt in all the layers of the pavement and can be recycled with virgin material in future applications. Studies by Uzarowski et al. (2008), Y. El-Hakim and L. Tighe (2012), Lee et al. (2002) conclude that perpetual pavements are cheaper and have a longer life as compared to conventional pavements over the same period of time. Uzarowski et al. (2008) also indicate that perpetual pavements have lower life-cycle costs and environmental impacts as compared to conventional deep strength pavements for construction and maintenance/rehabilitation phases. Y. El-Hakim and L. Tighe (2012) also confirm that even though the initial construction cost of perpetual pavements is greater than conventional pavements, the overall benefits of using perpetual pavements over the entire life cycle are higher. Hence, perpetual pavement technology improves highway construction sustainability by reducing the cost and long-term environmental impacts associated with frequent maintenance and rehabilitation operations. Another advancement in the field of asphalt materials is the use of warm mix asphalt (WMA) that requires lower energy and temperature for production as compared to the traditional hot mix asphalt (HMA). Comparative Life Cycle Assessment (LCA) study made by Leng and Al-Qadi (2011) between Warm Stone Mastic Asphalt (WSMA) and Hot Stone Mastic Asphalt (HSMA) show that WSMA reduces the energy consumption by 6.5% and the environmental impact score by about 6%. Additionally, the results indicate that the economic benefit of WSMA further increases by mixing it with 10% Reclaimed Asphalt Pavement (RAP). L. Von Quintus and

58 Mallela (2013), also reveal that WMA saves 15% of cost as compared to HMA. FHWA Sustainable Highways Sustainability Self-Evaluation Tool (INVEST) gives credit to projects that use WMA over HMA. Western Federal Lands is currently considering a transition from HMA to WMA due to the advantages associated with the use of WMA for the reconstruction of 1.3 miles of Forest Highway 26 (Sustainablehighways.org, 2017). Asphalt Recycling. Asphalt pavements can also be recycled and the recycled material can be mixed with the virgin material and binder. This will help in lowering the costs and environmental impacts associated with a project. Some of the innovative recycling methods have also proven to be cost-effective. Bemanian (2008) describes that the use of Cold In-Place Recycling (CIR) undertaken by the Nevada Department of Transportation (DOT) resulted in $600M cost savings. Additionally, the results indicate that CIR requires 80% less energy than HMA. Western Federal Lands got the highest score under the PD-20 section of INVEST due to the use of recycled compact aggregate base, reclaimed asphalt pavement (RAP), reused every piece of rock, recycled and reused 90% of minor structural elements, and the CIR method for the North Park road (Sustainablehighways.org, 2017). Delaware DOT attained platinum level in INVEST due to the use of recycled asphalt pavement, recycled asphalt shingle (RAS), recycled concrete aggregate (RCA), tire-derived aggregate, crumb rubber and cellulose fiber (Sustainablehighways.org 2017). Robinette & Epps (2010) show a significant reduction in cost and the environmental impact of a highway construction project due to the use of recycled materials such as RAP and RAS in HMA and innovative recycling techniques like CIR, full- depth reclamation and hot in-place recycling for maintenance and rehabilitation. Lee et al. (2010) reveal that the use of 15% Recycled Pavement Material (RPM) stabilized with 10% cementitious fly ash in the base resulted in 16% savings in energy, 20% reduction in global warming potential, and 21% reduction in the life cycle costs. Similarly, Lane & Eng (2008) reveals 52% reduction in Greenhouse Gas (GHG) emissions and 42% cost saving by using two types of in-situ recycling namely, CIR and Cold In-Place Recycled Expanded Asphalt Mix (CIREAM). Additionally, the study describes that the use of CIR/CIREAM causes less noise, improves safety and user convenience. Highway sustainability rating systems such as FHWA INVEST and Building Environmentally and Economically Sustainable Infrastructure-highways (BE2ST-in-highways) rate these technologies and methods favorably. Concrete Materials. In the area of concrete materials, Rao, Jha, and Misra (2007), Toutanji et al. (2004), Sutter (2016) have presented ways to reduce the impact of concrete pavements by replacing cement in concrete with supplementary cementitious materials such as fly ash and slag. Concrete can also be recycled; for example, Texas DOT used high strength and low permeability concrete mix and recycled benches for the construction of Corpus Christi Harbor Bridge that resulted in minimizing the air quality degradation and life cycle costs. Additionally, the study made use of industrial byproducts such as blast furnace slag, silica fume and fly ash in the Portland cement concrete (Sustainablehighways.org 2017). Santero, Loijos, and Ochsendorf, (2013) considered various approaches, many of which do not directly pertain to highway construction methods, even though they help reduce the impact of pavement life cycle emissions. Kim et al. (2013) developed a framework to calculate GHG emission from the material production and construction phase of reinforced concrete pavement construction. Hassan (2010) showed that the use of TiO2 coating for concrete pavement lowers the acidification, eutrophication, criteria air pollutants and smog formation.

59 Other Materials. Some studies have looked to estimate and reduce the emissions produced by the use of steel, wood, and rock. Paristech (2012) concluded that steel deck production and reinforcing steel production have highest environmental impacts. Zapata et al. (2005) determined that 94% energy is consumed for a continuous reinforced concrete pavement during the manufacture of cement and steel. Ohio DOT recycled more than 5 million pounds of steel (Sustainablehighways.org 2017). Hammervold et al. (2013) reveal that steel bridges produce highest environmental impacts and concrete bridge produces the least impacts in a comparative study between a steel box girder bridge, a concrete box girder bridge, and a wooden arch bridge. Western Federal Lands considered reusing the rock for the construction of North Park Road as the virgin rock material would need heating and washing before it can be used. This practice proved to be cost-effective (FHWA, 2017). 3.7.15 Safety 3.7.15.1 Definition  The Code of Federal Regulations define a competent individual in the context of safety as “capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous, or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate them” (OSHA, 2017). A sustainable highway pavement project must achieve superior safety performance and successfully implement procedures to protect the lives of the workers during construction (Gambatese and Tymvios, 2012). For the purposes of this analysis, safety practices considered during planning, design and operation and maintenance will not be addressed. 3.7.15.2 Relationship to Sustainability  Dimension Category Indicator Human Wellbeing Health & Happiness Safety Economic Wellbeing Project Economy Cost-Benefit Safety practices are in place to minimize or eliminate worker fatalities and injuries. These types of incidents erode the health of the individual workers, reduce the effectiveness of the organization and generate significant costs to the project schedule and budget. An effectively executed sustainable highway construction project must consider all aspects of safety practices throughout the life of the construction efforts (Rajendran and Gamabtese, 2009). 3.7.15.3 State‐of‐the‐Practice  The need for the safe construction practices can be broken down into three categories: humanitarian (moral reasons); economic (3 types of cost: direct cost of previous accidents, direct cost of each accident occurrence, indirect cost); and legal/regulatory requirements. All U.S. construction projects are required to meet the minimum safety standard as prescribed by the Occupational Safety and Health Administration (OSHA). According to OSHA’s 2015 statistics, the “heavy construction and engineering” category reported over 26,000 nonfatal occupational injuries and illnesses nationwide and over 15,000 (60%) of those cases resulted in days away from work (OSHA, 2017). Additionally, OSHA’s 2015 statistics indicate that the “heavy and civil engineering construction” industry falls in OSHA’s top 20 highest incident rates of nonfatal occupational injury and illnesses at nearly three times the average industry rate (2017). These safety incidents not only affect construction worker health, but they also decrease project productivity, increase schedule delays and increase contractor medical costs. Improved safety

60 practices offer opportunities to benefit from both a short and long-term perspective at a fraction of the upfront cost. According to OSHA, nonfatal injuries, sicknesses and fatalities produce an annual cost of about $170 billion (2017). OSHA claims that for every dollar invested in a safety program an organization can avoid four to six dollars in direct and indirect costs (2017). Beyond OSHA requirements, organizations typically have the flexibility to enforce more stringent (not less) standards. For example, Air Force Civil Engineer Squadrons in coordination with the Air Force Wing conduct recurring safety inspections in support of construction work on base. Currently, an incentive-based safety rating system is absent from highway construction practices (Rajendran and Gambatese, 2009). Even in the nationally recognized Leadership in Energy and Environmental Design (LEED) sustainable building rating system, safety characteristics and terminology are seldom mentioned (USGBC, 2016). In fact, a safety performance comparison of the early version of LEED versus non-LEED projects revealed similar safety performance (Rajendran, 2005). Conversely, an updated analysis of the safety performance of LEED versus non-LEED facilities produced mixed reviews (Gambatese and Tymvios, 2012). In other words, many credits do not impact safety performance, some credits escalate safety risks and some credits reduce safety risks (2012). The OSHA standard is the only enforceable rating system by which a highway construction project can evaluate its safety performance. Kim et al. investigated the source of highway construction safety incidents and discovered that the abundance of highway construction safety events occur within the following six categories: drainage, tunnel, installation, earth moving, paving and structure (2013). On a more tactical level, Hinze et al. conducted an analysis on the connection between construction safety best practices and safety performance (2013). The output of the study discovered a compelling association between 10 best safety practices and increased overall safety performance in construction projects (2013). The 10 best practices recognized by Hinze et al. as indicators of high safety performance in construction projects include “worker-observation programs, worker- safety perception surveys, tracking of first-aid injuries, supervisor involvement in policy making, active owner involvement in safety, site-specific safety training for managers, adequate safety staffing, 100 percent steel toe boot policy, on-site medical facilities and active contractor safety meeting participation” (2013). 3.7.15.4 Innovative Practices  Sustainable Construction Safety and Health Rating System (SCSH). Rajendran and Gambatese offer an incentive-based safety rating framework, the Sustainable Construction Safety and Health Rating System (SCSH), to achieve superior safety practices (2009). The SCSH covers a variety of sustainable construction practices but for the purposes of this analysis, only the rating system will be discussed. In 2006, the original version of the SCSH proposed by Rajendran and Gambatese was developed and was published in 2009, FIGURE 11 displays the most current version (2009; SCSH 2016).

61 FIGURE 11. Sustainable Construction Safety and Healthy Rating System (SCSH, 2016). Safety case studies from 25 different construction projects and an extensive literature review informed the development of the SCSH (Rajendran and Gambatese, 2009). Only two of the 25 projects used to generate the SCSH were transportation projects; however, the rating system can be used exclusively for highway construction practices if desired. Similar in structure to the LEED rating system, the output of the research produced a 50-element and 13 major category safety rating framework with accompanying points for each element (2009). The 13 major categories identified include (2009): 1. Project team selection 2. Safety and health in contracts 3. Safety and health professionals 4. Safety commitment 5. Safety planning 6. Training and education 7. Safety resources 8. Drug and alcohol program 9. Accident investigation and reporting 10. Employee involvement 11. Safety inspection

62 12. Safety accountability and performance measurement 13. Industrial hygiene practices Also, just like LEED, the project can receive the nationally recognized tiered achievement levels of Certified, Silver, Gold and Platinum depending on the points received (2009). Additionally, 25 elements must be fulfilled to satisfy the minimum requirement of the rating system (Rajendran and Gambatese, 2014). Although the SCSH rating system is still in its infancy stages in comparison to LEED, the rating system is now web-based (since 2011) and offers consulting services for construction projects (SCSH, 2016). FIGURE 12 provides the scorecard of a case study featured on the SCSH website (2016). FIGURE 12. Sustainable Construction Safety and Healthy Rating System Case Study (SCSH, 2016). In 2014, Rajendran and Gambatese published additional considerations of the SCSH rating system. The scope of the supplementary analysis included testing the SCSH framework on 64 projects from 2011 to 2013 (2014). The subsequent recommendations resulting from the updated data concluded that the structure of the current system should remain unchanged; however, innovation credits should be added to account for creative safety solutions (2014). Rajendran and Gambatese also noted that the SCSH website has been commonly frequented, but few contractors are applying the SCSH to their projects (2014). Although the construction industry

63 has not yet fully embraced the SCSH rating system, it remains a promising, pragmatic strategy to implement sustainable construction practices for highway construction projects. Aside from OSHA’s attempt to quantify the benefits of enhanced safety programs, the literature mostly captures qualitative impacts. Hinze et al. proposes that the number of safety techniques employed enhances safety effectiveness and “performance” on a job site (2013). Regarding safety practices, the primary impact of sustainable highway construction project is the protection of the project workers during construction. A sustainable project will safeguard construction workers from exposure to life altering hazards (Rajendran and Gambatese, 2009). Not only will effective safety practice benefit the worker during construction, it will also provide benefits long after the project is completed. 3.7.16 Employment 3.7.16.1 Definition  Employment is defined as “a person who is hired for a wage, salary, fee or payment to perform work for an employer” (Legal Dictionary, 2017). In the context of this investigation, it includes people hired as a direct result of the project or permanent employees working on the project. This encompasses policies that provide opportunity to traditionally disadvantaged business enterprises as well as under-represented minorities. The Federal Highway Administration (FHWA) prescribes the economic objectives inherent to a highway construction project which are typically driven by local interests (FHWA 2016). The local leadership usually determines the economic goals to pursue and not surprisingly, one of those considerations is typically the many facets of employment impacts in the local community (2016). Impacts generally include “number of jobs created and number of business establishments created” (2016). For the purposes of this analysis, employment considered during planning, design and operation and maintenance will not be addressed. 3.7.16.2 Relationship to Sustainability  Dimension Category Indicator Human Wellbeing Personal & Social Development Equality Income Distribution Economic Wellbeing External Economy Financial Impact Employment According to Toole and Carpenter, sustainable employment characteristics includes the development of social equity and capital which includes the employment of disadvantaged groups (2013). Stated another way, equitable employment opportunities should be offered to individuals that have been traditionally neglected (Picker, 2007). Picker suggests that a construction contract is another mechanism to secure social equity milestones (2007). 3.7.16.3 State‐of‐the‐Practice  In an effort to allow fair and equitable dissemination of business across the government enterprise, the Small Business Act was congressionally legislated in 1958 (2016). The Small Business statute establishes mechanisms by which small businesses, service-disabled veteran- owned small business, women-owned small businesses and other variations of small businesses can sufficiently compete.

64 Federal agencies have a high interest in the level of participation local businesses and the various categories of small businesses contribute to government funded work. Subsequently, a great deal of analytic driven scrutiny dictates who and how contractors are hired for local and federal government projects. Small businesses comprise nearly half of the U.S. worker capacity and support the sustainment of the nation’s economy when larger businesses reduce their workforce (Oberlander, 1996). The Small Business statute establishes mechanisms by which small businesses, service-disabled veteran-owned small business, women-owned small businesses and other variations of small businesses can sufficiently compete (2016). In fact, the U.S. Small Business Administration annually evaluates each federal agency in order to ensure the established goals are being met consistently (Small Business 2016). The evaluation model includes three categories by which to score small business and socio-economic progress: (1) prime contracting performance, (2) subcontracting performance and (3) plan progress report performance (Small Business, 2016). The prime and subcontracting categories analyze each agency’s progress regarding small businesses, small businesses owned by women (WOSB), small disadvantaged businesses (SDB), service-disabled veteran-owned small businesses (SDVOSB), and small businesses located in Historically Underutilized Business Zones (HUBZones) (Small Business, 2016). The plan progress report is an evaluation of the agency’s progress towards its own specific strategy, the Small Business Administration uses seven success factors to calculate agency performance (Small Business, 2016). The level of detail expressed in this model communicates the importance of local and small business consideration in government projects. One of the manifestations of nationwide interest in local and small business employment considerations is the level of detail provided in pavement construction analysis reports. Employment considerations and best management practices can oftentimes be found as part of the National Environmental Policy Act (NEPA) documentation process, specifically the Environmental Impact Statement (EIS). An EIS is required when “a proposed major federal action is determined to significantly affect the quality of the human environment” (EPA, 2017). Although an EIS is not completed on all pavement construction projects, an analysis of past projects can provide a glimpse into some of the employment considerations accounted for during the projects. The California Department of Transportation (DOT), Caltrans, submitted an EIS in support of its project to repair and improve just over a 13-mile stretch of State Route 58 (SR-58) in the San Bernadino County region (Caltrans 2014). The EIS examines each of the proposed courses of actions to complete the project and specifically provides employment impact considerations for each construction alternative. Of the four proposed alternatives, the “community impacts” category which included an analysis of the employment impacts was a significant driver in the selection of the “preferred” course of action (2014). The EIS noted that construction employment dropped by about 19 percent between 2008 and 2009 and this project would provide a short-term boost and support construction employment in the local area (2014). Secondary employment impacts were also considered. According to the EIS, Alternatives 1A and 3 would have negative impacts on the businesses in the local area (2014). In another example, Florida’s DOT submitted an EIS analyzing five construction alternatives to repair a 10-mile section of Krome Avenue in Miami-Dade County, Florida, see Figure 3 below (Florida DOT 2014). Unlike the Caltrans EIS, the Florida DOT EIS only evaluated the secondary business and residential employment impacts of the project within the economic category (2014).

65 The EIS did not address the construction employment considerations directly resulting from the project. 3.7.16.4 Innovative Practices  The Washington State Department of Transportation (WSDOT) submitted an Economics Technical Memorandum in support of its EIS for the State Route (SR) 520 Pontoon Construction project. The memo provided an analysis of alternatives for WSDOT’s proposal to build the floating bridge pontoons in the Grays Harbor area on the coast of western Washington (WSDOT 2010). The investigation examined the recent employment challenges in the local area and also explained how the local area could benefit from this project (WSDOT, 2010). Not only would the local community be injected with a short-term employment boost but the project quality would benefit as well since an inherent capability to perform this type of work resides within the Grays Harbor region (WSDOT, 2010). FIGURE 13 below estimates the economic impacts produced as a result of the pontoon construction (WSDOT, 2010). FIGURE 13. Direct, Indirect and Induced Employment Impacts of Pontoon Construction (WSDOT 2010). Regarding small business program goals, each state set its own objectives. California’s DOT (Caltrans) has set a SBE participation goal of 25 percent on its state funded contracts and a 12.5 percent goal Disadvantage Business Enterprise (DBE) goal on its federally funded contracts (Caltrans, 2016). In an analysis of seven California transportation projects, the DBE goals were either met or exceeded (Picker 2007). In another example, the WSDOT requires prime contractors to use SBE-certified contractors in support of 10 percent of the project total (WSDOT SBE 2016). WSDOT DBE goal is just over percent three percent (2016). The Maryland DOT did not advertise an SBE goal, but its proposed DBE goal was 30 percent for FY 2017-2019 (Maryland DOT 2016). FIGURE 14 captures the number of positive economic impacts found within specific project types most of which are highway construction efforts.

66 FIGURE 14. Number of Cases with Report Positive Direction of Economic Impact (Economic Development Research Group, 2012) Although the figure above is a step forward in objectively capturing the economic impacts of highway construction project; however, it is still rather subjective. The information found provides mainly subjective not objective information regarding costs, benefits and impacts. Broadly speaking, the construction costs of a highway project’s exclusion of or minimal contribution to employment of small, local and/or disadvantaged businesses include reduced flexibility, reduced diversity and reduced innovation (Oberlander, 1996). The long-term costs include an erosion of the nation’s small business workforce (1996). Small businesses, especially in the construction industry have a relatively high rate of failure, about 100 of every 10,000 small businesses fail (Bashford, 1996). In fact, Kale and Arditi contend that the first few years of a construction business, particularly new small businesses, are critical to the longevity of the construction company (1998). Conversely, the construction benefits of contributions to employment of small, local and/or disadvantaged businesses include increased flexibility, increased diversity and increased innovation (Oberlander, 1996). One of the short-term impacts of supporting small, local and/or disadvantaged businesses include increased competition thereby a strong likelihood of reduced construction costs (Bashford 1996). Additionally, support of local small businesses will likely increase flexibility and innovation during construction (Oberlander, 1996). 3.7.17 Training 3.7.17.1 Definition  According to the Occupational Health and Safety Administration (OSHA), construction safety training includes educating “workers and employers on the recognition, avoidance, abatement, and prevention of safety and health hazards in workplaces in the construction industry. The program also provides information regarding workers' rights, employer responsibilities, and how to file a complaint” (2017). The Department of Labor defines Registered Apprenticeship as a “proven approach for preparing workers for jobs while meeting the needs of business for a

67 highly-skilled workforce” (2017). For the purposes of this analysis, training considered during planning, design and operation and maintenance will not be addressed. 3.7.17.2 Relationship to Sustainability  Dimension Category Indicator Human Wellbeing Personal & Social Development Education One of the core tenants of implementing effective sustainable highway construction practices is to develop a practical education and training system. Education and training is a fundamental component necessary for attaining and sustaining high level highway construction operations. 3.7.17.3 State‐of‐the‐Practice  Safety. Investment in safety training is oftentimes a low priority and in times of tight budgets, non-mandatory training programs are among the first to absorb funds reductions (Haslam et al., 2015). Haslam et al argue that in the short term, these decisions reduce training costs but are strategically short sighted (Haslam et al., 2015). Wanberg et al. (2013) contend that slashing safety program budgets directly contribute to increased nonfatal injuries and accompanying medical costs. Profits generally increase with increased investment in safety training (Haslam et al., 2015). According to OSHA’s 2015 statistics, the “heavy construction and engineering” category reported over 26,000 nonfatal occupational injuries and illnesses nationwide and over 15,000 (60%) of those cases resulted in days away from work (OSHA, 2017). OSHA’s 2015 statistics indicate that the “heavy and civil engineering construction” industry falls in OSHA’s top 20 highest incident rates of nonfatal occupational injury and illnesses at nearly three times the average industry rate (OSHA, 2017). OSHA offers several safety training courses (10-hour, 30- hour, 500 level) to encourage safety awareness and application. According to Namian et al, the recommended cure to remedy most safety deficiencies in the workplace is increased training (2016). In spite of the increased focus and attention on safety in recent years, over 70% of construction-related injuries can be traced back to an insufficient awareness of approved safety practices (Namian et al., 2016). According to Jeelani et al, only about 42% of construction workers on average are able to recognize on-site hazards (2016). In other words, most construction workers typically underestimate risks and overlook or do not recognize work site hazards (Namian et al 2016). This systemic neglect across the construction enterprise can be partially attributed to below average training programs. All too often, a preponderance of training regimens are executed with ineffective curricula and inexperienced instructors (Namian et al 2016). In other words, amount of training is not enough to be effective, substance and quality is critical. Lectures alone will not inspire change (Heath and Heath 2010). Workers must be given the “direction” and “motivation” to “change behavior” so that workers are self-assured enough to act with boldness (2010). With that paradigm shift in mind, only a small fraction, approximately 10 to 15 percent, of the safety training program contributions produce actionable benefits (Namian et al., 2016). Apprentice. The U.S. Secretary of Labor has oversight of the nation’s apprenticeship program and establishes broad policies regarding apprenticeship requirements. Generally speaking, apprenticeship training is a function of time (over 2,000 hours), “competency”, or a combination time and competency (blended approach) (U.S. DOL, 2017). Each state has the flexibility to apply equal or more stringent requirements (U.S. DOL, 2017). For example, the state of

68 Washington’s apprenticeship training for a construction equipment operator must include at least 6,000 hours of on-the-job (Washington 2015). Specifically, the operator must complete 1,500 hours of training on four defined categories of training to include track type, rubber tire, hoisting type and stationery type (Washington, 2015). Washington is unique, many state apprenticeship standards are identical to the federal standards. FIGURE 15 captures the general apprenticeship methods among the different categories of trades within the construction industry, broadly speaking, the civil trades have the highest percentage of on-the-job training (Wang et al., 2008). FIGURE 15. Reported Percentage of Formal and On-The-Job Training by Trades (Wang et al., 2008). 3.7.17.4 Innovative Practices  Safety. Tam and Fung propose the creation of federal regulations with prescriptive language making it mandatory for all project managers to complete safety training prior to executing oversight of any projects (2012). The American Road and Transportation Builders Association (ARTBA) offers a Safety Certification for Transportation Project Professionals which is another level of credentialing in addition to the OSHA safety courses (ARTBA, 2017). This certification is an advanced level of safety credentialing and improves an individual’s mastery of the application of highway infrastructure safety incident prevention (2017). The Safety Certification for Transportation Project Professionals exam is $500-$600 but must be preceded by the appropriate prerequisite requirements such as the OSHA 10-hour, 30-hour and 500 level courses (ARTBA, 2017). Namian et al (2016) suggest construction companies adopt robust, interactive and engaging training methods facilitated by qualified instructors that include blended learning curriculum methods. In 2013, the Air Force’s Civil Engineer School developed and launched a 10- and 30- hour construction safety course modeled after OSHA’s courses of the same name (Delorit and Burwinkle 2014). Even though the courses are an archetype of the OSHA courses, the Civil Engineer School has reworked the curriculum to meet Air Force civil engineer needs (2014). Similarly, Tam and Fung recommend reworking safety course curricula to include nine learning objectives targeted at optimally streamlining the course (2012). These strategies are uncommon;

69 just below half of construction project safety training programs have adopted the robust methods described above (Namian et al., 2016). Apprenticeship. The literature search revealed limited above-and-beyond examples regarding construction apprenticeship. Bosche et al advocates for a more aggressive implementation of advanced technological application of apprenticeship training, namely mixed reality (MR) systems (2016). Although the recommendation is commendable, the realistic application of virtual reality apprenticeship training will likely not be implemented in the construction industry over the next five years. The Air Force’s enlisted civil engineer career field and education training plan (CFETP) is a robust form of apprenticeship training and produces highly qualified civil engineer technicians and leaders. The Air Force civil engineer career field has multiple specialties but for the purpose of brevity, the training of a pavement and construction equipment operator will be highlighted. Apprenticeship training for this career field includes five major categories: (1) Initial Skills Training, (2) Upgrade Training, (3) Qualification Training, (4) Advanced Training and (5) Proficiency Training (Air Force 2013). To satisfy all of the requirements in the plan, the Airman must complete four levels of career development coursework and upgrade training requirements, complete two one-year periods of on-the-job training, complete four extensive Air Force courses and pursue a Community College degree (2013). For more detailed information, reference the Air Force Pavements and Construction Equipment Operator CFETP. Data to quantify the costs and benefits of safety and apprenticeship training is limited. The cost of OSHA 10- and 30- courses are $79 and $169 respectively while OSHA 500, OSHA’s train- the-trainer course, is $725 (OSHA 2017). Regarding apprenticeship grants and training, $90 million was provided to the Department of Labor in Fiscal Year 2016, it was the first time ever funding was provided for this initiative (Department of Labor 2017). In the absence of federal funding for apprenticeship training, data was not found. Construction companies can establish mechanisms to enhance the safety program thereby reducing short and long-term costs as well as strengthening “operational efficiency” (Tam and Fung 2011). 3.7.18 Public Outreach 3.7.18.1 Definition  The U.S. Department of Transportation defines “public outreach” as “the process of communicating with groups and individuals with the intent of both providing and obtaining information about the impacts of a proposed or in-progress work zone” (Mallett et al., 2005). Ideally, public outreach can be used to improve road user / work zone safety, reduce negative work zone impacts to the local economy, and educate the public. 3.7.18.2 Relationship to Sustainability  Dimension Category Indicator Human Wellbeing Health & Happiness Personal & Social Development Safety Education Economic Wellbeing External Economy Financial Impact

70 Safety. Public outreach plays an important role in the safety of traffic/road users and worker/jobsite safety. While dangers to road users and workers is not mutually exclusive, there is a relationship between road users and workers, where road users can cause the potential danger to worker and vice versa. As a result, unsafe traffic conditions will likely occur endangering road users and jobsite workers. Informing the public of construction on highways allows for public to be more cautious while traveling. Ehsaei et al. (2015) discovered that through public outreach, traffic calming measures were implemented and community support was also garnered. Traffic calming improves safety for both workers on job site and road users in traffic. The community support adds to road users and residents in the community to be more compliant in the standard safety measures. Education. Public outreach is frequently cited as a critical factor in the success of large projects and can be a form of education, which might result in wider community support (e.g., Lopez del Puerto and Shane, 2014). For instance, in a Chinese case study Wang et al. (2016) showed that dedicating a portion of the public outreach program to educating the public regarding the impact of the construction project allowed the public to evaluate the project more rationally and increase understanding. This allows for effective communication in which both parties understand each other, allowing the public to cooperate with the construction. Done (2007) found that when the public understood the information, their attitudes were more positive and their feedbacks were more productive. Nadafianshahamabadi et al. (2017) wrote on the differences in values and goals of experts in construction and those in the affected community are different due to the fact that experts have the luxury of looking at the big picture, while the members in the affected community focus on immediate challenges and needs. Effective communication from education may allow construction experts and members of the community to work together to produce effective projects in solving the community’s needs. Local Economy. Public outreach can influence traffic demand, which, in turn, can impact the cost of transporting goods as well as accessibility of local businesses. Usually, impacts are measured only as an overall user delay cost and not separated into business impacts and costs of goods transport. For example, Lee, Kim, Harvey, & Asce (2006) reviewed the use of intelligent transportation systems (ITS) to provide to the public real time travel information for a major freeway rehabilitation project. They concluded the net benefit of this form of public outreach was $3.6 million in road user and delay cost savings.   3.7.18.3 State‐of‐the‐Practice  Minooei et al. (2016) compiled information on community outreach tools that are currently being used by state departments of transportation through surveys. Each tool used targets different specific goals for outreach: 1. Creating traffic avoidance during construction 2. Increasing driver awareness in construction zones 3. Decreasing impatient behaviors in drivers in construction zones 4. Building trust with the public Minooei’s (2016) survey (results shown in Figures 22 and 23) shows that the two most commonly used public outreach tools are variable sign boards and static temporary signage.

71 These two are required by law and thus determine the minimum standard at every construction site. The subsequent five most commonly used tools are: 1. Project-specific websites 2. Town hall meetings 3. Planned interview with newspaper 4. Social media 5. Planned interview with television FIGURE 16. Effectiveness of public outreach tools used by DOTs (Minooei, 2016).

72 FIGURE 17. Effectiveness versus frequency of usage of public outreach tools (Minooei, 2016). FIGURE 16 shows the effectiveness of each tool on the mentioned goals above. Of the seven most commonly used tools, social media ranks the highest in effectiveness among them in traffic avoidance and decreasing impatience behavior in drivers. Variable signboards are the most effective in increasing driver’s awareness of construction. Town hall meetings are the most effective out of the seven most commonly used outreach tools in building trust with the public. Over exaggeration of events during public outreach can produce a negative impact on the message. In the case of closing down one of the freeway for reconstruction in LA, California, public officials opted for using the radio station as their platform for public outreach (Brown et al., 2016). The message was over exaggerated to stir user change; however, no significant changes in traffic occurred during the construction. This example emphasizes the importance of the optics of public outreach messages. In essence, over sensationalizing the impacts to traffic flow damages public trust and as a result, the public is less likely to heed future public outreach messages. 3.7.18.4 Innovative Practices  Mobile Application. Minooei et al.’s survey (2016) has shown that the most effective tools in traffic avoidance includes decreasing impatient behaviors in drivers, increasing driver’s awareness and building trust is mobile application. Currently, technology has progressed to the point where the majority of the population has access to a smartphone, easing access to real time updates. Lee and Thomas (2006) have shown that using ITS technology in public outreach has a net benefit of $3.6 million in saving. The preliminary traffic analysis modeled the cost from interference from construction to be $6.2 million, and through ITS, it decreased to $2.4 million. Factoring in the cost of using the devices, which was roughly $1.4 million in device purchases, leasing and maintenance, the net benefit produced a cost savings of about $3.6 million dollars.

73 The data in the last 10 years suggest that real time data availability to the public produces costs savings and encourages traffic avoidance as well as increases driver’s awareness. Despite the data trends, transportation agencies have been slow to embrace the usage of mobile applications. Intensive public outreach program. Ehsaei et al. explored a San Francisco project that successfully implemented a public outreach program during corridor rehabilitation. During open houses, representatives from associations and interest groups affected by this project were invited to participate. Informational boards, interactive displays and project team members were available as resources during the open houses. Online surveys were also conducted through a tool called MetroQuest to gather feedback on the project and to understand the community’s priorities in order to improve the project. The survey was deemed successful as over one thousand people responded, representing a high level of public interest and engagement. The residents who lived adjacent to the corridor were sent an informational letter and a frequently asked question memo. Additionally, the project team facilitated a conversational “coffee meeting” to field more in-depth questions from the community. The outreach program was rated successful; traffic calming measures were integrated and the project garnered a high level of community support. 3.7.19 Noise 3.7.19.1 Definition  Noise is defined broadly as “a class of sounds that are considered unwanted and may adversely affect the health and wellbeing of individuals or populations” (Gunderson et al., 2015). This is related to the construction of highway projects by its impacts on workers and those in the area immediately surrounding the project. The reduction of noise is directly related to the three main forms of noise control (source, path, receptor) and the control of noise for workers on the projects. This section addresses noise reduction due to highway construction but does not include discussion on highway operational noise reduction. 3.7.19.2 Relationship to Sustainability  Dimension Category Indicator Human Wellbeing Health & Happiness Healthy Life Safety Environmental Wellbeing Nature & Environment Ecological Resources Noise pollution can significantly decrease the health and quality of life of those around the project. Sustained noise of over 70 decibels can lead to health and hearing impairments (Zannin, 2002). Noise can also cause tinnitus, which is the inability to perceive silence due to ringing in one’s ears (Gunderson et al., 2015). In addition, safety is also an indicator addressed by this topic as hearing loss in workers can occur if proper noise reduction steps are not taken on the worksite. Masterson et al. (2016) estimated that around 22 million workers in the United States are annually exposed to hazardous occupational noise. According to Masterson et al. (2016) “occupational hearing loss, primarily caused by high noise exposure, is the most common U.S. work-related illness” giving high urgency to reduce noise in highway construction projects (2016). Noise pollution does not only effect humans with major ecological consequences in the form of disruption to wildlife near noise generating sources. These effects can be seen in the form of hearing loss, as animal’s ears are similar to humans, and masking where animals are

74 unable to hear natural cues and other animals’ signals (EPA, 1978). Additionally, animals may exhibit less researched impacts such as loss of reproduction or abandonment or territory (EPA, 1978). 3.7.19.3 State‐of‐the‐Practice  Mitigation of noise from construction is vital to the health and safety of humans and wildlife. It can reduce the quality of life of citizens and decrease productivity, causing local municipalities to impose maximum noise levels based on type of area (residential, commercial, etc.) and time of day (Gilchrist, 2003). It is also important to consider the workers in these projects and their exposure to unsafe levels of noise. There was limited literature on innovative practices specifically relating to noise reduction for workers, but proper safety equipment and some source controls can help to mitigate risks to employees. OSHA (2011) has given general recommendations of keeping average noise levels below 85 decibels (dB) for full shifts and limit noise over 100 dB to one hour. These levels are significantly above the 70 dB that Zannin (2002) found was unsafe, so there is room for significant improvement in noise reduction specifically for workers. Prior to construction, algorithms can be used to estimate noise at receptors based on a variety of variables. This allows potential problems to be accounted for and mitigated in the final project design (Gilchrist, 2003). Noise control methods during construction can be broken down into three categories: source, path, and receptor control. With regard to source control, the Central Artery Tunnel (CA/T) project in Boston used innovative methods such as testing every piece of machinery coming onto the site for its noise contribution. Noise from machinery increases as it ages, so operating newer equipment can result in substantial source noise reduction. European countries have a strict Blue Angel Certification that equipment manufacturers must meet resulting in an up to 15 dB decrease in the noise produced by each piece of machinery compared to those in the United States. Path control is the next best method of minimizing noise before it reaches the receptors. This can be done through increasing the absorption, distance, and deflection of the noise or noise producing equipment. Noise barriers are the most common method of path control and can result in a decrease of 10 to 20 dB but were only found to be cost effective if a 10 dB or more decrease was required (Gilchrist, 2003). Additionally, increasing the distance from the receptor can decrease noise by a small amount. After using the previous options, receptor control can be used to bring noise levels to an acceptable level as a last option. This method of reduction is the least cost-effective method and can also consist of relocating individuals while noisy activity takes place (Knauer, 2006). 3.7.19.4 Innovative Practices  OSHA regulates noise exposure to humans on jobsites; however, impacts to wildlife and the environment are regulated by other government agencies. Reduction of noise for wildlife. In rural or unpopulated areas, noise is not a concern as a human health impact. Rather, ecological impacts may be of concern. It has been found that some species of birds will avoid noise sources such as highways or highway construction by up to three kilometers (Kaseloo, 2004). For this reason, contractors working in sensitive areas can take steps such as not working during the two hours after sunrise and before sunset (Kaseloo, 2004). National Parks also seeks to minimize all artificial noise in order to keep the natural soundscape for visitors. The Natural Sounds Program seeks to “protect, maintain and restore acoustic environments in the National Parks” giving staunch opposition to any unnecessary construction

75 noise (Freimund and Nicholas, 2009). For example, on a Western Federal Lands (WFL) road project in Mount Rainier National Park the contractor was limited to 92 dB near Western Spotted Owl (listed as “Threatened”) nesting areas and was required to use mufflers and limit idling time of construction equipment. Backup alarm modifications. The CA/T project brought about advancements in decreasing the backup alarm noise (Schexnayder, 2001). A survey of various DOTs found backup alarms resulted in the highest complaints of noise in major projects (Hancher, 2001). The CA/T project tested alternative alarms such as radar and visual warning along with alarms that can be turned down for nighttime construction. Additionally, OSHA approved some agencies proposal to disconnect backup alarms at night in favor of using a spotter (Bryden and Mace, 2002). Example. As discussed earlier, the Boston CA/T project was innovative in its use of various noise control techniques. This project resulted in significant advances in backup alarm noise mitigation with adjustable noise alarms for nighttime construction and use of spotters in areas sensitive to noise (Thalheimer, 2000). Additionally, a “Window Treatment Cost Benefit Index” was developed which helps to determine if window treatments for additional noise reduction were necessary (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 (Thalheimer, 2000). The cost of noise reduction can vary also based on what methods of control are used, for example source control versus receptor control which is prohibitively expensive for minimal results (Thalheimer, 2000). A benefit of noise control is that projects can be completed on time since without proper noise abatement strategies, complaints and possible legal issues may slow down project delivery (Thalheimer, 2000). This helps to decrease the overall cost of the project since time is a very valuable resource during construction. These benefits are confined to when the project is being built as post-construction there are no tangible benefits from noise reduction during construction. 3.7.20 Light pollution 3.7.20.1 Definition  The International Dark-Sky Association (2017) defines light pollution as the “…inappropriate or excessive use of artificial light”. The four components of light pollution are (International Dark- Sky Association, 2017):  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. This section addresses light pollution related to temporary lighting used during nighttime roadway construction and its contribution to light pollution. 3.7.20.2 Relationship to Sustainability  Dimension Category Indicator Human Wellbeing Health & Happiness Healthy Life Safety Environmental Wellbeing Nature & Environment Ecological resources

76 Light pollution affects human health and safety as well as ecological systems. Though light has obvious benefits to human society, excess light and light pollution can have negative human health impacts. Surveys have indicated public displeasure in some cases with freeway lighting that inadvertently lights their yards and houses during the night (Khan, 2003). In addition, light pollution has seriously reduced the aesthetic value of the night sky with over two-thirds of the U.S. population already having lost the ability to see the one omnipresent Milky Way galaxy with the naked eye (Cinzano et al., 2001). Light pollution in the form of glare also poses a safety risk to motorists adjacent to a work zone. Glare visible to adjacent drivers reduces contrast and visibility and can increase collision likelihood. Light pollution can negatively impact a wide range of plant and animal species. Outdoor sky glow effects can be significant enough that nighttime conditions mimic those naturally observed at twilight (Navara and Nelson, 2007). Estimates indicate that 20% of land in the continental U.S. is located within 150 ft. of a roadway (Ritters and Wickham, 2003). Because of this, the ecological consequences of light pollution from roadways have large potential impacts. In the plant kingdom, artificial light can disrupt the natural mechanisms used to regulate flowering and other seasonal actions (Rich and Longcore, 2005). Impacts on the animal kingdom are more diverse and cause a wide array of ecosystem alteration. In some cases, light pollution can be devastating. For instance, sea turtle hatchlings navigate their way to the ocean based on the relative darkness of land mass, and artificial lights can render this ability completely ineffective (Salmon, 2003). Nocturnal animals are also particularly vulnerable. Street lighting limits the flying routes of endangered bat species and can cause habitat fragmentation (Stone et al., 2009). When nocturnal habitats are fragmented, populations become increasingly at risk of loss of genetic diversity and local extinction. Increased lighting conditions can alter reproductive behavior in animals such as frogs, which are warier in the absence of darkness, or glow worms, which communicate visually to attract a mate (Longcore and Rich, 2004; Navara and Nelson, 2007). 3.7.20.3 State‐of‐the‐Practice  Nighttime work zone lighting is a balance between providing enough illumination for workers to see and minimizing light pollution that affects the surrounding area and vehicles traveling past the work zone (Hancher, 2001). Ellis et al. (2003) recommend three levels of work zone illumination:  Category I (54 lux minimum). General illumination of the work zone for safety purposes.  Category II (108 lux minimum) Illumination on or around construction equipment.  Category III (216 lux minimum). Illumination for high visual difficulty operations (e.g., crack and pothole filling, joint sealing, critical connections, electrical and mechanical maintenance). NCHRP Report 498 Illumination Guidelines for Nighttime Highway Work (Ellis et al., 2003) contains recommended guidelines for night work illumination, illumination design, and temporary lighting.

77 3.7.20.4 Innovative Practices  Work zone glare reduction: Glare can be reduced through planning, light positioning, and certain types of lighting equipment. Algorithms, such as CONLIGHT, can be used to model and design work zone lighting to allow for ideal placement to maximize illuminance and uniformity while minimizing glare and lighting costs (El-Rayes and Hyari, 2005). El-Rayes and Hyari (2005) found their estimation methods to be within 12% of actual conditions on the construction sites they tested. Hassan et al. (2011) found that increasing mounting height and reducing the aiming angle to a maximum of 30 degrees above vertical can greatly minimize the disabling glare for drivers and pedestrians (2011). Generally, good modeling and lighting design can decrease costs based on the amount of unnecessary lighting removed, while changes in mounting height generally incur no added cost. Balloon lights can also be used to reduce light pollution in the form of glare. Balloon lights use a diffuser which results in less illuminance but greatly decreases disabling glare for drivers and increases lighting uniformity (Hassan et al., 2011). El- Reyes et al. (2003) found that glare from their tested balloon lights was only 10-15% that of conventional lighting equipment while still providing a large diameter of lighting (El-Rayes et al. (2003). Semi-permanent high-mast lighting: 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 generally positive results. For example, Freyssinier et al. (2006) observed a New York highway construction project and determined that semi-permanent high- mast lighting cost 16% more than traditional lighting but saved substantial time each night as workers did not have to set up portable lighting. Freyssinier et al. (2006) recommend semi- permanent high-mast lighting for longer duration projects only (about 4 months or longer) and point out that there are 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). Freyssinier et al. (2006) propose a short evaluation table that could be used to determine the appropriateness of semi-permanent high-mast lighting for any roadway construction project. 3.7.21 Design for Constructability 3.7.21.1 Definition  Design for Constructability (DfC) or Buildability (DfB) collectively refers to the technical considerations of a highway’s design that can facilitate the physical construction, maintenance, salvaging, or disassembly of infrastructure. AISC considers Design for Deconstruction (DfD, aka Disassembly or Deconstructability) an extension of DfC principles with a more specific focus on recovering (salvaging) value from components or materials after initial construction (Crowther 2002; Pulaski et al. 2004). This discussion focuses on DfC principles that can be incorporated into the design phase and affect the physical processes of construction, maintenance, or disassembly of a pavement. Practices are motivated by the notion that time and resources spent in the design phase will have a greater impact on the overall project performance and cost less than if those efforts were otherwise spent later in the project’s lifetime, a relationship suggested by the MacLeamy Curve (Construction Users Roundtable 2004). Although the majority of established DfC or DfD practices are applied primarily to vertical construction, these practices may also apply to highway infrastructure including bridges.

78 Although the list of case studies establishing DfD practices in the highway industry are few, existing practices focusing on life-cycle engineering, material selection/reuse/recycling, and landfill avoidance all align with the core intents of DfD principles. Most attempts to define DfC refer to a paradigm of extending the useful life of material in a closed-loop system throughout its life-cycle, avoiding the need for material production from virgin materials (entering the loop) or disposing a pavement’s materials (exiting the loop) (Hosseini et al. 2015; Iacovidou and Purnell 2016; Pulaski et al. 2004; Santero et al. 2011; Santos et al. 2015; United States Environmental Protection Agency 2015; University of Washington 2011). In their handbook on Design for Deconstruction, the US EPA cites several principles that are consistent with most literature attempting to identify the intents of DfC: 1. Extending an infrastructure’s useful service life is the optimal reuse case because its value is greatest when material use is aligned with its original design intent (i.e. as a roadway) because it minimizes the demand for virgin materials as well as energy for processing or transportation. 2. Salvaging a structure (in any manner) recovers some value from its components or materials but recovered materials no longer contribute to a functional use (e.g. as a bridge or pavement). Inevitably, this reduces the inherent value of the materials in addition requiring additional costs or energy for transportation and reprocessing. 3. Demolition and transportation to landfill eliminates the value of the material by effectively ending its useful life and should be a last resort as a result. Furthermore, waste disposal also results in additional transportation, energy for treatments (e.g. hazardous waste), and loss of landfill space in addition to fees. The lack of a standard taxonomy for DfC in the construction industry has resulted in a multiplicity of terms that align with or encompass one or more DfC principles but frequently have overlapping sustainability intents. TABLE 13 describes variations or extensions of DfC practices commonly cited in literature (not exhaustive), including their intent, focus, and perceived benefits and tradeoffs.

79 TABLE 13. Design for Constructability: Frequently Cited Practices and their Perceived Benefits Design for Adaptive Reuse (DfAR) [a.k.a. Repurposing]  Incorporate intention to adapt a pavement (or components) in design for eventual reuse in another structure  because pavement (or components) still have structural integrity; minimize amount of deconstruction,  transportation, or reprocessing required (Iacovidou and Purnell 2016).  Design for Manufacture and Assembly (DfMA) [a.k.a. Prefabrication, Modularity]  Consider whether pavement sections or components would result in a better overall performance if  prefabricated (or partially constructed) off‐site. Modular components can facilitate disassembly procedures and  retain some functional value compared to recycled materials, which may require additional reprocessing.  This  includes the consideration of environmental impacts, material and fuel consumption, and waste generation  throughout the project life‐cycle including end‐of‐life (Iacovidou and Purnell 2016).   Design for Reuse (DfR)  Incorporate intention to adapt a pavement (or components) into design by in‐situ reprocessing materials for  reuse within the structure during maintenance. Even though energy/emissions result from reprocessing, proper  design may reduce the demand for virgin material consumption and avoid transportation or landfill demands  (Iacovidou and Purnell 2016; Santero et al. 2011).   Design for Deconstruction (DfD) [a.k.a. Disassembly, Decommissioning]  Attempt to facilitate deconstruction by embedding procedural efficiencies into the design and the construction  or maintenance activities required. Maximize the use of recycled materials. This will incur larger off‐site  transportation requirements, inventory costs, and additional energy/emissions for reprocessing degraded  materials compared to DfR (Iacovidou and Purnell 2016; Santero et al. 2011), but minimize the amount of  materials hauled to landfill.  DfD refers to recycling material, although some authors like McDonough and  Braungart distinguish ‘downcycling’ and ‘upcycling’ as more specific terms for recycling, distinguished by the  extent to which a material’s value changes after reprocessing off‐site (McDonough and Braungart 2002).  Design for Logistics (DfL) or Reverse Logistics (DfRL)  Similar to DfD, but particularly focusing on the amount of physical transportation demanded by a paving  strategy. This includes the optimization of transportation and consequently (operational) energy demands and  emissions, material efficiency, inventory costs, and landfill requirements (Hosseini et al. 2015).  Design for Safety (DfS) [a.k.a. Prevention Through Design (PtD), Design for Construction Safety (DfCS)]  DfS refers to the idea that construction or maintenance procedures should not inherently endanger humans (via  exposure to danger or risk) and that such considerations will have the greatest impact if identified and  addressed in the design phase (Toole et al. 2017). Incorporating safety into design may help avoid physical risks  to both construction workers and roadway users alike, as well as improve project economics through avoided  delays and costs associated with worker injuries, contract claims and disputes, or lawsuits.  3.7.21.2 Relationship to Sustainability  Dimension Category Indicator Environmental Wellbeing Nature & Environment Natural Resources Climate & Energy Clean Land Consumption GHG Emissions Economic Wellbeing Project Economy Cost-Benefit DfC and DfD practices focus primarily on reducing the consumption of virgin resources and clean land (landfill avoidance) (Guy and Ciarimboli 2010). It is estimated that at least 70% of environmental impacts associated with construction material is due to production energy (embodied energy) and about 30-40% of solid landfill waste is attributed to construction demolition waste in developed countries (Crowther 2016; Iacovidou and Purnell 2016). As a result, DfD practices related to material selection aim to extend the useful service life of construction material in order to divert construction waste from landfills, potentially reducing

80 construction costs, embodied energy, and carbon emissions from material processing or production (Hosseini et al. 2015; Rios et al. 2015). While there is consensus that DfC primarily addresses environmentally themed indicators, researchers also include economic sustainability as a primary motivator for implementing DfD practices (Ahn et al. 2013). Despite potentially larger initial costs and perceptions regarding structural performance, salvaged materials tend to cost less and can foster economic growth by presenting opportunities to further develop markets for salvaged / reprocessed materials (Crowther 2002; Iacovidou and Purnell 2016; Rios et al. 2015). Though fewer in number, some literature also associate DfD practices with the social wellbeing dimension of sustainability because design decisions can affect the safety of construction workers and notions of inter- generational equity due to the long intended service lives of highways (Ahn et al. 2013). 3.7.21.3 State‐of‐the‐Practice  DfC strategies were originally intended for vertical construction. There are no federal regulations that govern or obligate DfC for highway construction specifically, let alone for construction in general. DfC strategies found in literature were originally conceived for the building industry but many can be extended to highway construction directly. Other strategies may require re-interpretation; e.g. mechanical building systems are analogous to utilities beneath a pavement when designing for accessibility. TABLE 14 collects 29 distinct DfC strategies identified in literature and have divided among five categories for clarity: (1) Access and Tolerance, (2) Complexity / Simplicity, (3) Information and Communication, (4) Materials and Connections Selection, and (5) Safety and Risk. The paving industry practices DfC indirectly through material management. The US EPA states that the overarching goal of DfD is to minimize the consumption of raw materials by responsibly planning for the end of a materials’ life (2015). Accordingly, regulations for recycled/reused content in pavements could be considered DfC practices because they ultimately result in the reduced consumption for raw materials. The Greenroads Rating System, a 3rd-party sustainability rating systems which rates and awards sustainable paving construction projects, have defined practices related to DfC that go beyond regulatory obligations. The system includes several material-conservation themed credits that are among the highest pursued and achieved by certified projects (Lew et al. 2016). Although no quantitative information regarding the extent of these achievements has been published, projects are rewarded for achieving 50-90% reuse of existing pavement materials, and 10-50% of recycled materials (20-60% if subbase elements are included). DfC practices are still relevant to but less effective for existing pavements. While existing highways are designed with target service lives, they are physically maintained with perpetual life-cycles intended. As DfC is an emerging concept, most existing highway facilities were not knowingly designed and constructed adhering to DfC principles. Nevertheless, principles of DfC can still apply to roadway maintenance and rehabilitation jobs (including decommissioning / disassembly) although options are naturally more limited and potentially less effective. Iacovidou and Purnell distinguish these DfC intervention practices as simply ‘deconstruction’ rather than ‘design for deconstruction’ practices (Iacovidou and Purnell 2016). In these cases, however, ratio of recovered value to effort is diminished and may be less economically attractive for many projects without DfC in mind. Among others factors, this value tradeoff is considered a

81 major obstacle preventing wider adoption of DfC practices within the building industry (Iacovidou and Purnell 2016). TABLE 14. DfD Strategies Identified in Literature   *Sources Strategy  [1]  [2]  [3]  [4]  [5]  Access and Tolerance  Design connection, components, or assemblies that are accessible and visible  X  X  X  X  Separate utilities / mechanical systems from structure  X  X  X  X  Design for human access and performance limits  X  X  Provide realistic tolerances for repeated use  X  Size components to suit means of handling or accommodate deconstruction logistics  X Complexity / Simplicity  Minimize number of different building components and materials  X  X  X  X  X  Maximize clarity / simplicity for assembly or disassembly; minimize/ reduce complexity  X  X  X  Design components or systems for modularity, interchangeability, prefabrication, pre‐assembly,  mass production, or standardization  X  X  X  X  X  Allow for parallel assembly  X  X  Simplify, standardize, and minimize the number of connections  X  X  X  X  Provide means of handling and aligning components  X  X  Reduce labor intensity or required skill level for construction/disassembly  X  X  Design for flexibility and adaptability  X  Use open, standard, or simplified grids or layouts for structural system  X  X  X  Design disassembly process that uses common tools and equipment  X  X  Information and Communication  Provide easily‐accessible information identifying building component properties,  assembly/disassembly methods, and other information about the structure/space  X  X  X  X  Identify points of disassembly  X  Identify material reuse potential  X  Bar coding / labelling of materials  X  Material / Connection Selection  Select fittings, fasteners, adhesives and sealants that allow for quicker disassembly and facilitate the  removal of reusable materials  X  Prioritize mechanical connections; minimize or eliminate chemical connections  X  X  X  X  Use durable, salvaged/reusable/recyclable materials in design that will retain value after repeated  use and are worth recovering  X  X  X  X  X  Use lightweight materials and components  X  Minimize use of toxic materials that can compromise reuse potential of construction components  X  X  Use of locally sources and/or salvaged material  X  Select construction components with service lives longer than that of structure to enable their reuse  X  Minimize use of composite materials  X  Safety and Risk  Incorporate safe deconstruction for and reduce risk to workers by allowing movement, equipment  and site access, and material flow      X  X  *Sources: [1] Iacovidou and Purnell, 2016; [2] Crowther, 2016; [3] US EPA, 2015; [4] Guy and Ciarimboli, 2010; [5] AISC, 2004 Prevailing perceptions as barriers In lieu of compelling quantitative data, research efforts have attempted to identify procedural barriers to DfC qualitatively through surveys and literature review. Ahn et al. found that lack of knowledge, limited stock, unfamiliarity, associated risk, and cost of sustainable materials were among the top 10 perceived barriers to implementing sustainable construction (2013). Iacovidou and Purnell found that the lack of standard specifications addressing material reuse, lack of

82 experience with (de)construction techniques, availability of tools for implementing deconstruction specifically, not incorporating DfC principles into initial design, and variation in quality were the most cited barriers to implementing DfC practices for materials (2016). Finally, Toole et al. found that the vast majority of his respondents (79 case study and 182 industry surveys) had no existing knowledge of Prevention for Design (i.e. Design for Safety), but agreed that such practices are beneficial and worth attempting (2017). Toole suggested that because safety in design is voluntary, it is often excluded or not explicitly obligated in contract documents, further contributing to the general lack of knowledge of PtD principles. Data barriers and metrics of performance The scarcity of demonstration construction projects showcasing DfC benefits may be attributed to the lack of quantitative information linking design choices to impact or project performance (Iacovidou and Purnell 2016). Quantitative methods such as life-cycle inventory (LCI), life-cycle assessment (LCA), and life-cycle cost assessment (LCCA) are commonly relied upon to quantify and compare the benefits of materials and their associated placement techniques. Despite their growing acceptance, the data complexity, steep learning curve, and inconsistent inclusion/exclusion boundaries across studies have resulted in examples that are largely incompatible or incomparable and cannot be generalized for construction practices (Santero et al. 2011). To make further progress with quantifying DfC practices, future research must focus on standardization to improve compatibility, a consensus on metrics for comparing materials and processes, or data acquisition and integration (Ahn et al. 2013; Iacovidou and Purnell 2016; Santero et al. 2011). Furthermore, a lack of a standard taxonomy with actionable indicators or metrics to compare choices prevents agencies from developing effective policy incentives, educational or training materials (knowledge), and secondary markets supporting DfC practices from maturing and becoming competitive (Ahn et al. 2013; Iacovidou and Purnell 2016). An effective typology system should capture three primary aspects of material recovery: physical material properties, recovery process, and the originally intended material use (Iacovidou and Purnell 2016) . Iacovidou and Purnell also recommend employing a ‘reuse potential’ metric (see Appendix III) to qualify the material recovery efforts and suggest that ‘smart technologies’ related to cataloging, integrating, and accessing material data could rapidly accelerate the creation of more definitive data to quantify the benefits of DfC practices. 3.7.21.4 Innovative Practices  There were no found documented case studies of highways or bridges designed for buildability or deconstruction in the United States. The FHWA was founded in 1967 so in 2017 at age 50, it is unlikely that such strategies were documented given the typical design life of highways is between 35 to 50 years. Another possible explanation is that some current best practices embody principles of DfC but are not commonly recognized by the industry as applications of DfC. Moreover, most existing case studies of DfC focus on vertical (building) construction rather than horizontal construction and heavy civil specifically. Several notable examples related to DfC are presented to demonstrate potential applications and interpretations of DfC. Perpetual Pavements. In a Canadian case study of test section of perpetual pavements on Highway 403 (near Toronto) and Highway 401 (near Quebec), the authors found the cost to be 30% higher than conventional Canadian pavement designs (El-Hakim and Tighe 2012). Over a

83 70-year design life however, the researchers estimated that the perpetual pavement yielded a net present value only 4% higher than conventional designs. The perpetual pavement was about 67% thicker, consisted of recycled materials and more durable materials like stone matrix asphalt, and required roughly 25% fewer maintenance activities. Consequently, perpetual pavement design could be an application of DfC because the design intends to extend the useful service life of materials (landfill avoidance), reduce maintenance closures and consequently user costs, as well as reduce emissions associated with transportation or material reprocessing. Precast Pavement in Highways. Well documented by the FHWA in 27 states (Tayabji and Brink 2015), the process of building Precast pavements construction is fundamentally different from most in-situ methods because construction is partially done off-site in laboratory conditions ((Soutsos et al. 2011). The design of the pavement can be complimented with recycled materials and pre-tensioning, which may further reduce the required pavement thickness and consequently fewer materials in general (Merritt et al. 2007; Merritt and Tayabji 2009; Portland Cement Association 2010). In cases where traffic volume is high or inclement weather is prone, this is an appealing strategy because the pavement design allows for overnight construction and can avoid substantial amounts user costs characteristic of longer closures and lengthy curing times (Portland Cement Association 2010). However, researchers found that Precast pavements have higher construction costs and require a greater number of closures than conventional pavements (Buch 2007; Merritt and Tayabji 2009; Tayabji and Hall 2010). Precast Pavements could be considered applications of DfC because the construction process includes the reduction of materials, clearer disassembly joints, modular repairs, reduced users delay and costs, and worker exposure to risk. Oakland Bay Bridge Deconstruction (2013 to present). Although not originally designed with DfC or DfD strategies, the Oakland Bay Bridge in California is a notable example of a modern bridge deconstruction (service life of 80 years from 1933 to 2013). Compared to demolition, the process of deconstruction is expecting completion in 2018 for a total of 5 years. California has adopted the Bay Bridge Steel Awareness Program that awards artists, designers, and firms with salvaged steel from the bay bridge, effectively avoiding the landfill as the steel was not intended for reuse (Schuler 2016). Although it is difficult to say whether DfC principles have expedited the disassembly process, the case study is a current example of landfill avoidance and material recycling, two common characteristics of DfC strategies. London Olympic Games 2012. The London Olympics Games (LOG) of 2012 is a notable example of infrastructure built with DfC/DfD principles and resulted in the Olympic lightest stadium that used only a quarter of steel compared to the Beijing Olympic Stadium and was partly disassembled (downsized) following the games (Crowther 2016). However, Flyvberg observed that although the London Olympic Games resulted in the expensive Olympic Games infrastructure, it exhibited justly slightly above the average in terms of % overrun compared to Olympics Games from 1968 to 2012 (Flyvbjerg and Stewart 2012). Consequently, there appears to be a clear tradeoff between higher initial construction costs and an adaptable structure that facilitates disassembly.