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the agencies consider energy usage when selecting Although most agencies have environmental pavement preservation and maintenance treatments. analysis incorporated into their design and Both of these are areas where the use of preventive construction operations, many maintenance maintenance treatments in a pavement preservation practitioners are not familiar with how they program can have a noticeable effect. Many of the could or should be applied to maintenance treatments are emulsion-based, with comparatively and preservation decisions. low emissions. Similarly, providing quantitative measures for differences among energy use among the various treatments would be a valuable tool in CASE STUDIES treatment selection. As part of this report, eight case studies were selected to demonstrate how agencies might apply Summary environmental sustainability factors to their mainte- nance programs. Information for the case studies was This chapter examines the current state of the obtained from technical publications. Each case study practice related to the environmental sustainability was selected to demonstrate a specific aspect of prac- impact factor areas and their application to pave- tice related to environmental sustainability. The case ment preservation programs and maintenance treat- studies were drawn from the literature. Several sus- ments. The recycled and alternative materials tainable transportation case studies are available authorization is the most prevalent. Although it is through the AASHTO Center for Environmental not explicitly stated, the role of pavement in-service Excellence (CEE 2010d). Each case study provides a monitoring and pavement management is also com- basis for understanding the context of how pavement mon. If implemented properly, a sustainable pave- preservation and maintenance can be evaluated. ment management program emerges, because the However, again, there is limited explicit information pavement monitoring system triggers pavement on how in practice agencies are carrying quantifying preservation activities, which in turn extend the ser- sustainable preservation and maintenance treatments. vice life of the pavement and reduce the impact to In any case, this section has involved identifying the environment in all categories. In short, keeping some examples of environmental stewardship. Each good roads good is the most effective way to sustain case study is presented in a similar manner. the service life of a road without consuming signif- icant amounts of energy, virgin materials, and non- renewable resources, which automatically reduces Case Study Descriptions air, water, and noise pollution. A recent study of the The case studies were drawn from agencies across Georgia DOT network-level pavement management the United States and in Canada, encompassing a system (Wang et al. 2010) demonstrated that such a range of climates and reflecting a variety of program system also makes economic sense. The report types (Table 7). found that a robust in-service pavement monitoring system "will help decision makers address the ques- Case Study 1: Arizona Department tion of paying for roadway preservation now at a of Transportation lower cost or later at a much higher cost" (Wang et al. 2010). Further examination and quantification of The Arizona DOT (ADOT) developed a compre- this impact could be examined in future work as the hensive environmental stewardship program (Kober direct policies and practices to pavement preserva- 2004). The program involved an overarching envi- tion and maintenance treatments could be explicitly ronmental performance evaluation and development reviewed for these environmental sustainability impact of a plan for implementing it within ADOT. It factor areas. In terms of noise pollution, water quality, includes leadership and stewardship; planning, man- and air quality there is clearly an opportunity agement, and compliance; environmental elements to incorporate these environmental sustainability of core business policies and procedures; recycling impact factor areas into preservation and mainte- and waste reduction; water management; and vari- nance operations. ous other areas. Table 8 briefly summarizes how the The following conclusion was reached in this ADOT program relates to the seven environmental chapter: sustainability impact factor areas. Specific elements 13

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Table 7 Case study program summary Case Study Agency/Location Reason for Inclusion Environmental Stewardship Program Arizona DOT, Comprehensive system-wide frame- Phoenix, Arizona, U.S. work for a DOT Transportation Sustainability Plan Oregon DOT, Evaluation of air quality and water Salem, Oregon, U.S. quality at a system level Sustainable Highway Materials Washington State DOT, Evaluation using a practical and Olympia, Washington, U.S. straight-forward approach to assessing sustainability impact factor areas GreenPave Ministry of Transportation Ontario Evaluation using a practical and Toronto, Ontario, Canada straight-forward approach to assessing sustainability impact factor areas Dirt and Gravel Maintenance Program Pennsylvania State Conservation Comprehensive assessment of dirt Commission, Pennsylvania, U.S. and gravel road maintenance Greenworks Program City of Philadelphia, Comprehensive city overview of Pennsylvania, U.S. sustainability impact factor areas GreenLITES Program New York State DOT Utilizes a spreadsheet-based self- Albany, New York, U.S. assessment of design that could be adapted to the design/selection of pavement preservation and maintenance treatments Sustainable Land Transport New Zealand Transport Agency Provides specific guidance for Wellington, New Zealand low-volume roads. Table 8 ADOT environmental stewardship business Sustainability Impact Factor Area Description/Relevance to Pavement Preservation and Maintenance Virgin Material Usage/Alternative Throughout the document concerted emphasis on limiting virgin material Material Usage usage and alternative material usage No direct quantification on pavement preservation and maintenance Program for Pavement In-Service Usage of updated manuals and management practices encourage Monitoring and Management environmental stewardship No direct quantification on pavement preservation and maintenance Noise Direction to mitigate traffic noise Air Quality/Emissions Emphasis is placed on reducing impacts to the air through proper maintenance of equipment and appropriate operations No direct quantification on pavement preservation and maintenance Water Quality Development of protocols to reduce sediment into streams and ensure proper storm water management No direct quantification on pavement preservation and maintenance Energy Usage Addresses a holistic approach to saving energy including indirect savings by simplifying maintenance paperwork, minimizing travel through web conferencing, etc. Advocates using energy audits to quantify pavement preservation and maintenance energy consumption 14

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of the ADOT program involved highway maintenance Oregon's polices with economic, social, and envi- manual updates; usage of a maintenance management ronmental stewardship. This philosophy is being system; environmental evaluation on routine mainte- reflected in both their short-term and long-term nance areas; and development of best management goals. As part of this, the Oregon DOT (ODOT) practices for paved and unpaved surfaces including has developed a Maintenance Environmental Man- paving equipment cleaning, paving staging areas, and agement System, which is directed at "minimizing material stockpiling, erosion, and sediment pollution the environmental impacts of maintenance of the control and disposal of equipment. transportation system throughout Oregon while pro- The ADOT program reinforces the commitment viding an effective transportation system that sup- to environmental stewardship throughout the orga- ports economic activities" (ODOT 2004). One of the nization and provides a system-level analysis for the specific outcomes is to "reduce adverse impacts of agency to gauge its success. In this case study, six of transportation on air quality and water quality." the identified seven environmental sustainability Overall, the system provides a holistic evaluation impact factor areas apply. The quantification of sus- on how ODOT performs its road and bridge mainte- tainable preservation and maintenance techniques nance practices. As noted here, it has relevance to within the environmental sustainability impact factor preservation and maintenance treatments although it areas context could be accomplished if the program does not specifically quantify anything beyond recy- is modified to permit the collection and assembly of cling of pavements. Table 9 provides a summary of environmental sustainability performance evaluation some of the key features and how they relate to the (Kober 2004). This ADOT documentation could environmental sustainability impact factor areas iden- serve as a strong basis for development for practical tified in this synthesis. guidelines. The ODOT environmental sustainability plan ini- tially focuses on practices at the maintenance yards to Case Study 2: Oregon Department ensure that operations do not adversely impact air of Transportation quality and water quality. Additionally, it furnishes The state of Oregon recently started a transporta- specific recycling targets for 193 bridges that are tion environmental sustainability plan to develop programmed to be replaced as part of a multi-billion Table 9 ODOT emergency management system case study facts Sustainability Impact Factor Area Description/Relevance to Pavement Preservation and Maintenance Virgin Material/Alternative Sets forth an "Environmental Management System" for bridge demolition Material Usage that focuses on maximizing recycling Recycling target set to quantify the amount of recycling in 193 bridge projects. Pavements associated with these bridges are included in the goal Air Quality/Emissions Focus on reducing pollutants in the air Pollutants identified as ozone, particulate matter, nitrogen oxides, carbon monoxide, sulfur dioxide, toxins, and carbon dioxide Lower particulate matter related to gravel roads by paving them Encourage multimodal transportation, thus having impacts on pavement preservation and maintenance treatments No direct quantification of pavement treatments and associated air quality Water Quality ODOT implementing best management practices to transportation infrastructure to improve water quality with special attention to avoid contamination of water Development of integrated vegetation management program to protect environment No direct quantification to pavement treatments and associated water quality Energy Usage Directs consideration of fuel consumption in decision making Source: ODOT (2004). 15

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dollar infrastructure renewal program. Within the plan impact factor areas are taken into consideration in there is an opportunity to evaluate preservation and the WSDOT plan. It is already producing good stew- maintenance techniques, although details of exactly ardship in several of the environmental sustainability how that can be accomplished are not available. Given impact factor areas and identifies pavement preser- the available information provided, ODOT is reaching vation and maintenance as important to achieving its targets as outlined. Another important aspect of this long-life pavements. Through the further development case study is that this initiative is successful given it is of specific guidelines related to the environmental sus- strongly supported both financially and morally by the tainability impact factor areas for pavement preser- governor and the director of ODOT. This is a critical vation and maintenance, this agency would be well component to follow through and support. positioned to implement them. They have a good basis to expand this practice area further. Case Study 3: Washington State Department of Transportation Case Study 4: GreenPave: Ministry of Transportation of Ontario The Washington State DOT (WSDOT) promotes sustainable highway materials through the reuse and The new GreenPave tool builds on more than recycling of materials; use of warm-mix asphalt; 20 years of research, development, and implementa- reducing the need to replace infrastructure by proper tion of green initiative at the Ministry of Transporta- design, construction, and maintenance; use of pave- tion of Ontario (MTO). MTO has recently developed ment management (the Washington State Pavement a green rating system for pavements. The program Management System) to incur the lowest life-cycle focuses on assessing the greenness of flexible and cost proactive usage of recycled asphalt pavement rigid pavement designs and their construction (MTO and recycled concrete aggregate pavements, hot in- 2010). Subsequent maintenance is not considered in place recycling, cold in-place recycling, asphalt shin- the analysis. GreenPave is loosely based on LEEDTM gles, alternative hydraulic cements, and restoration certification, but it was also influenced by Green- of construction sites with plants and shrubs. Table 10 roads, GreenLITES, and the Transportation Associ- summarizes the initiatives and relevance to the envi- ation of Canada (TAC) Guide for Green Roads (TAC ronmental sustainability impact factor areas. 2010). Table 11 summarizes the key features and WSDOT is very proactive in the promotion of how they relate to the environmental sustainability sustainable pavement design, construction, and reha- impact factor areas. bilitation. As noted in the table summary, three of The GreenPave tool is a direct effort to quantify the identified seven environmental sustainability overall environmental sustainability within MTO's Table 10 WSDOT sustainable pavements Description/Relevance to Pavement Preservation Sustainability Impact Factor Areas and Maintenance Treatments Virgin Material Usage/Alternative Encourages recycling of RAP and RCA, usage of HIR, CIR, usage of Material Usage hydraulic cements that are recycled, and use of asphalt shingles Most of these would relate to design and construction of new or rehabili- tated pavements. However, similar applications to maintenance could be incorporated Program for Pavement in Service Attempts to optimize sustainable designs through active PMS and Monitoring and Management monitoring Already examines proper preservation and maintenance so development of guidelines to promote sustainable maintenance would be possible Air Quality/Emissions Using warm asphalt on a trial basis that recognizes lower emissions Directed at design, construction, and rehabilitation, but could be modified for use in preservation and maintenance RAP = recycled asphalt pavement; RCA = recycled concrete aggregate; HIR = hot in-place recycling; CIR = cold in-place recycling; PMS = pavement management system. 16

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Table 11 MTO Greenpave case study factors Description/Relevance to Pavement Preservation Sustainability Impact Factor Areas and Maintenance Treatments Virgin Material Usage and Alternative This is directed at optimizing usage/reusage of recycled materials and to Material Usage minimize material transportation distances A total of 14 points is assigned to this category Directed at design, construction, and rehabilitation, but possibly could be modified for use with pavement preservation and maintenance treatments Program for Pavement In-Service Attempts to optimize sustainable designs to include long-life pavements, Monitoring and Management permeable pavement, noise mitigating pavements, and pavements that minimize the heat island effect Total of nine points is assigned to this category Directed at design, construction, and rehabilitation, but possibly could be modified for use with pavement preservation and maintenance treatments Noise Directs the use of means to minimize road noise Air Quality/Emissions Minimizes energy consumption and GHG emissions Total of nine points is assigned to this category Directed at design, construction, and rehabilitation, but possibly could be modified for use with pavement preservation and maintenance treatments Energy Usage Directs consideration of fuel consumption in decision making Other: Innovation and Design Process Recognizes innovation and exemplary efforts to foster sustainable pavement designs Total of four points is assigned to this category Directed at design, construction, and rehabilitation, but possibly could be modified for use with pavement preservation and maintenance treatments Source: MTO (2010). GHG = greenhouse gas. long-standing Green Pavement Initiatives (GPI) pro- that could be extended for development of sustain- gram (Lane 2010). GPI has been in place since 1988 able pavement preservation and maintenance points and credits itself for recycling more than 1.2 million and ratings. Overall, this initiative is gaining momen- tonnes of aggregate as well as the following reduc- tum as it is strongly supported by senior MTO man- tions in greenhouse gases: agement and is being developed in partnership with industry through consultation with the Ontario Hot 88,400 tonnes of carbon dioxide, Mix Producers Association and the Ready Mixed 720 tonnes of nitrous oxide, and Concrete Association of Ontario. 15,400 tonnes of sulphur dioxide (Lane 2010). Case Study 5: Pennsylvania's This case study applies to five of the seven envi- Conservation Commission ronmental sustainability factors, along with an addi- tional evaluation category of innovation and design The Pennsylvania State Conservation Commis- process. The MTO GreenPave program would result sion (PSCC) has a Dirt and Gravel Maintenance in the rating of projects whereby bronze (710 points), Program. It provides training and funding to local silver (1114 points), gold (1519 points), and tril- road-owning entities, usually townships, to mitigate lium (20+ points) levels would be recognized in a sediment pollution to streams originating from dirt and similar manner as LEEDTM. There is also a proposal gravel roads (PSCC 2010). The sediment from roads, to calculate a green discounted life-cycle cost and farms, construction sites, logging, and various other set targets province wide to obtain a specified num- sources is the largest contributor of pollutants to the ber of green pavement designs per year. Finally, a state's waters. Pennsylvania has the largest network Green Paver of the year award may also be consid- of rivers and streams in the United States, with the ered. This program does provide a good framework exception of Alaska, so their protection is of critical 17

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Table 12 Pennsylvania State Conservation Commission Sustainability Impact Factor Area Description/Relevance to Pavement Preservation and Maintenance Water Quality Focus on reducing roadway sediment runoff into rivers and streams Primary source of sediment from dirt and gravel roads Program provides funding to conservation districts and focuses on sensitive maintenance of unpaved roads Provides funding to control the amount of sediment from dirt and gravel roads and focuses on good pavement preservation and maintenance practices Source: PSCC (2010). importance. Although gravel road maintenance often Case Study 6: City of Philadelphia-- involves getting water quickly off the road, this results Greenworks Philadelphia in tons of sediment that enters into the state streams. The Greenworks program is a local action plan The presence of the sediment can cause great harm to for climate change and emphasizes clean air, better the ecosystem, including disruption of natural stream management of stormwater, and increasing in-service order and flow, damage to fish species through direct condition of city streets and roads (Nutter 2009). abrasion to body and gills, loss of fish spawning areas, The plan's "Target 13--Increase the State of Good sediment killing small organisms in the streambed, Repair in Resilient Infrastructure" creates a direct and a filling of dams and reservoirs (PSCC 2010). relationship to sustainable pavement preservation and Table 12 summarizes the Pennsylvania's State Dirt maintenance treatments. The Greenworks plan and Gravel Maintenance Program and its relevance to requires the city of Philadelphia to establish a pave- the environmental sustainability impact factor areas. ment in-service monitoring and management system The program works with public and private enti- to permit its Department of Streets to better identify ties through a task force to assist with local projects and address pavement maintenance issues. It also and decision making, education and training, simpli- sets forth targets to encourage recycling of pavement fied grant applications and publicprivate partnerships. materials. The plan is quite ambitious and will require It creates standards and requirements for the construc- substantial city resources ($35 million per year) to tion and environmental protection of dirt and gravel execute (Nutter 2009). Table 13 summarizes the key roads (PSCC 2010). This program received the 2000 features and how they relate to the environmental Governor's Award for Environmental Excellence. sustainability impact factor areas. Table 13 City of Philadelphia Description/Relevance to Pavement Preservation Sustainability Impact Factor Area and Maintenance Treatments Virgin Material Usage and Alternative Encourages recycling in road work; mentions hot-in place recycling and Material Usage recycled asphalt pavement Framework could provide incentive for application to pavement preser- vation and maintenance treatments Program for Pavement In-Service Requires establishment of pavement monitoring system Monitoring and Management Air Quality/Emissions Attempts to reduce carbon dioxide, methane, and nitrous oxide Focuses primarily on types of vehicles; there could be an opportunity to use the framework to achieve goals Water Quality Increased rainfall and associated runoff will affect the ability to process storm water and subsequently impact water quality Could be applied to pavement area Source: Nutter (2009). 18

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Greenworks is a multidimensional program that environmental sustainability that have not been pre- has several key target areas, including four of the envi- viously used in NYSDOT operations" (NYSDOT ronmental sustainability impact factor areas. Although 2009). This provision, although generic, could be used there is a direct mention of sustainable pavement to gain credit for pavement preservation and main- preservation and maintenance, the development of tenance practices that are not specifically included guidelines related to the environmental sustainability in the approved list of green activities. For example, impact factor areas would fit well within the Green- the use of shotblasting to restore microtexture and works program. macrotexture on concrete pavement and asphalt pavement is very sustainable, as it does not consume any virgin material and recycles both the shot and Case Study 7: New York State Department potentially the collected residue (Gransberg 2009). of Transportation GreenLITES Adding shotblasting to the pavement preservation GreenLITES is a "project design certification and maintenance programs could result in additional program" for projects that will be delivered as typi- GreenLITES credit under 27F. In short, the pave- cal New York State DOT (NYSDOT) construction ments portion of this program could be used as an projects (NYSDOT 2009). It is very comprehensive initial template for creating an agency program to and may be the most pointed of the DOT programs encourage and measure environmental sustainability because it references pavement preservation and inside its current pavement preservation and mainte- maintenance treatments, such as diamond grinding, nance program. Table 14 summarizes the environ- crack sealing, and liquid asphalt treatments. Addi- mental sustainability impact factor areas and their tionally, there is a provision in category 27F, Inno- relevance to the NYSDOT GreenLITES program. vative and/or Unlisted Activities, to accord credit "to GreenLITES provides a rational methodology pavement related practices that significantly build that is based on previous work in the area of mea- upon GreenLITES categories and objectives or that suring environmental sustainability of infrastruc- incorporate significant innovations in transportation ture design and construction, such as LEEDTM and Table 14 NYSDOT Greenlites Sustainability Impact Factor Area Description/Relevance to Pavement Preservation and Maintenance Virgin Material Usage and Alternative Emphasis on limiting virgin material usage and alternative material Material Usage usage is stressed in the program Quantification on pavement preservation and maintenance done through credits earned, use of recycled tire rubber, and recycled asphalt pavement Noise Specific reference to inclusion of measures for reducing pavement noise Quantification on pavement preservation and maintenance done through credits earned for diamond grinding Air Quality/Emissions Emphasis is placed on reducing impacts to the air through proper main- tenance of equipment and appropriate operations Quantification on pavement preservation and maintenance done through credits earned Water Quality Development of protocols to reduce sediment into streams and ensure proper storm water management Quantification on pavement preservation and maintenance done through credits earned Energy Usage Credit for reducing electricity and petroleum consumption Quantification on pavement preservation and maintenance done through credits earned for documented analysis of design that reduces carbon footprint Other: Innovation System encourages engineers to extend the scope of the program to pre- viously unlisted techniques that comply with the spirit of the program Quantification on pavement preservation and maintenance done through credits earned in Innovative and/or Unlisted Category 19