Transportation infrastructure investments have long-lasting implications not only on the transportation system but also on the larger environmental, economic, and social systems with which transportation interacts. As stated on the sustainability page of the American Association of State Highway and Transportation Officials (AASHTO), the sustainability of the transportation system is critical because the sector is responsible for 10 percent of the world's gross domestic product, 22 percent of global energy consumption, 25 percent of fossil fuel burning, and 30 percent of global air pollution and greenhouse gases. Transportation agencies generally do not have processes and tools to gather and sort through information on such system interactions in order to make more effective investment decisions.
Sustainable transportation is generally used to refer to transportation that contributes to the sustainable development of the community that owns and uses the system. A principal component of sustainable development, sustainable transportation tends to be defined in different ways by different agencies depending on specific priorities or constraints. However, it essentially includes effective and efficient system performance, with positive impacts on the social quality of life, economic competitiveness and the preservation of the natural environment. More recently, transportation agencies in the US have begun to develop processes and tools to gather and analyze information on system interactions in order to make more effective investment decisions. Other countries have conducted research on transportation and sustainability for several years and as a result, international experiences can provide several valuable lessons. Examples of international experiences that might be of interest include a wide range of planning and analysis tools, including Spatial Planning, Backcasting and Strategic Sustainability Analysis (SSA). Backcasting is an analytical tool that recasts the decision-making environment to better understand potential futures by deciding on the desired status of selected critical factors (e.g., related to livability, environment, and economy). Policies are then developed and implemented to promote technological innovation as well as the behaviors to achieve the desired future state. Spatial planning techniques consider spatial relationships within the context of a wide range of planning criteria, e.g. jobs/housing locations to promote economic development, environmental preservation and social quality of life. SSA, used by both Germany and the Organization for Economic Cooperation and Development to assess transportation impacts, is a model-based methodology for analyzing complex transportation decisions with long-term time horizons; interlinked with environmental, economic, and social systems; and with a spatial scope above the project-level. These types of techniques when applied at broader geographic scales, e.g. regionally or mega-regionally, tend to have more potential to promote global and regional economic competitiveness and set a general context for activities at state, county, or city levels of decision making.
There are several examples of international efforts to address sustainability, and a great deal of them have a broader scope because they are legally authorized and have allocated funding to address sustainability for entire nations and even regions. New Zealand (NZ) and the United Kingdom (UK) have national strategies for sustainable transportation. In the case of the UK, this strategy is part of a broader national sustainable development strategy involving a number of sectors and institutions, e.g., energy and the environment. The European Union (EU) has also developed a sustainable development strategy having a transportation component. Nations and regions that invest in the development of broader sustainable development visions, goals and objectives are likely to develop more comprehensive solutions involving multiple sectors and several institutions with related functions. They are also more likely to identify confounding effects of policies that may be good for one sector, but not particularly effective for another, thus motivating agencies to work together to achieve systemic and enduring solutions.
National support for sustainability in the United States appears to be growing and one indication is the Transit Investments for Greenhouse Gas and Energy Reduction grant program included in the American Recovery and Reinvestment Act. Another development is the announcement of a partnership between the US Department of Transportation (USDOT), the US Department of Housing and Urban Development (HUD), and the US Environmental Protection Agency (EPA) for the Sustainable Communities Initiative (or Livable Communities Partnership), which represents a national movement toward collaboration among appropriate agencies to achieve sustainable development. The partnership in particular represents a broadening of the sustainability definition, as prior legislation and federal directives were focused on environmental protection and environmental justice. In addition to the environmental review process prescribed by the National Environmental Policy Act of 1969 (NEPA), US transportation agencies have been subject to planning requirements from the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) and the Transportation Equity Act for the 21st Century (TEA-21). ISTEA and TEA-21 established mandates for early identification of environmental impacts and for public involvement in the environmental review process. More recently, the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) of 2003 added mandates for Environmental Streamlining and Stewardship (1,2). Additional state and local policy guidance is provided by the Federal Highways Administration (FHWA) and AASHTO through periodic publications, workshops, and online resources. Notably, FHWA released the Sustainable Highways Self Evaluation Tool, a web-based initiative for learning about sustainability and evaluating the sustainability of roadway projects (75).
The Sustainable Highways Self Evaluation Tool is a web-based tool and resource to help transportation agencies make roadway projects more sustainable. The tool takes a lifecycle approach to sustainable roadway projects, by evaluating them from system and project planning through design, construction, and operations and maintenance. It is a voluntary, self-evaluation tool with three components. First, it offers education about sustainability principles, the FHWA Sustainable Highways Initiative, and how to apply the evaluation tool. Second, it provides examples of sustainable highways best practices. And third, it has an online form for scoring projects, programs, and agency practices. The evaluation component includes 68 credits organized into three categories: system planning, project development, and operations and maintenance. The scores provide a way quantify sustainability, information that transportation agencies can use to inform decision-making or demonstrate a commitment to sustainability. The tool is available at http://www.sustainablehighways.org.
Even though the US does not have a national sustainable transportation strategy to guide policy development, individual states and metropolitan areas have begun to develop their own policies, programs, and methodologies for improving transportation system sustainability. The purpose of this guidebook is to take advantage of sustainability practices around the world and describe alternatives and opportunities for implementing such practices and pointing out potential barriers. More specifically, this guidebook examines how sustainability considerations could be better incorporated into transportation planning. It focuses on practices that refine, enhance, or redefine a step(s) in the planning process, (for example, developing sustainability plans or climate change action plans). For this reason, project-level practices that have been sponsored by organizations like FHWA or AASHTO, particularly in the area of environmental sustainability, are not covered in the guidebook, although they clearly can have an important part in a transportation agency's sustainability program.
Many of the practices presented in this guidebook were identified from a survey of sustainability planning practices at state DOTs (refer to the survey questions in Chapter 3) and from a literature review of U.S. and international practices. As the survey results indicated, there are considerable differences in the level and type of sustainability activities in state DOTs, due in part to financial challenges, legal constraints, the presence of external support (from state government or other agencies), or different priorities. In addition, practices are undertaken at different stages of the planning process and focus on different geographic scales (local, regional, state). Because of the diversity in the practices described, this guidebook is relevant to any agency that engages in transportation planning.
The guidebook presents critical issues involved in planning for sustainable transportation systems (Chapter 2) and then reviews current practices in the US and abroad that address these issues (Chapter 3). One of the major challenges in implementing sustainability assessment for planning relates to data availability, so Chapter 4 describes potential data sources and examples of how data has been used in sustainability-related initiatives. Chapter 5 consists of case studies of sustainability practices that have been implemented by US transportation agencies or comparable agencies abroad. It also describes cutting-edge evaluation methods that have not been widely applied by transportation agencies, but could greatly advance sustainability evaluation and planning.
There is a wide range of sustainability activities that can occur at transportation agencies, the focus of which put agencies on very different pathways to similar destinations. Agencies that have supporting legislation with allocated funding to pursue sustainability goals are in a different place than those that do not. An agency that already has a sustainability plan is starting from a very different place than one that has just started to talk about sustainability. Agencies that have already created interdisciplinary teams or hired new staff to deal with sustainability issues are at an advantage to those lacking personnel and experience. How an agency uses this guidebook will depend on their particular sustainability objectives and the extent of their current sustainability practices. Chapters 1, 2, and 3 can be considered a sustainability primer - a useful resource for agencies or transportation professionals that have little experience with sustainability or that want to focus on new areas that are unsustainable. The case studies presented in Chapter 5 vary widely in their level of comprehensiveness, issues addressed, and phases of the planning process impacted. Collectively, the case studies provide agencies with a range of examples from which they can select what best meets their sustainability priorities and needs.
The classic definition of sustainable development that has enjoyed the broadest acceptance was offered by the United Nation's Brundtland Commission in 1987: Meeting the needs of the present generation without compromising the ability of future generations to meet their own needs. Several definitions have emerged since. However, most definitions embrace the Brundtland concept with three fundamental components: the economy, the environment and social quality of life - also called the triple bottom line or three-legged stool of sustainable development. Successful application of the principles of sustainable development lies in translating this worthy idea into practical guidance for making decisions: i.e., setting goals, implementing practices and measuring results.
Sustainable development and sustainability are sometimes used interchangeably. Sustainable development can be viewed as the process of achieving sustainability. It relates primarily to achieving a satisfying life for all while staying within the limits of nature. To achieve sustainability, we need to balance the basic conflict between the two competing goals of ensuring an acceptable quality of life (QOL) and living within the limits of nature. If either of these elements is not achieved, we will fail in our efforts to reach sustainability (3). Figure 1-1 depicts four zones of development distinguishing among sustainable development, sustainability, and developing sustainably once sustainability has been achieved.
Sustainable development occurs as progress is made from Zones A, B or C to D. Zone A is the state where a community is denied access to natural resources and cannot meet basic needs: for example, a community that has not developed the technology necessary to develop its natural resources and improve its QOL. Zone B, on the other hand, is the state where the environment is being degraded and yet people are not enjoying a satisfying QOL, a zone where several developing countries find themselves today. Zone C is the state where people enjoy a satisfying QOL but their natural assets are not being adequately protected, a zone where several developed countries find themselves today. Zone D, which can be considered the zone of sustainability, is a state where a high QOL has been achieved (and is being maintained or elevated) without degrading the environment. A community in Zone D can be said to have achieved sustainability in the sense that their existence does not jeopardize the natural resource capital base. But even within Zone D, there is room for "developing sustainably." A community in Zone D that finds better ways of achieving higher QOL with reduced negative impacts on its natural resources would be moving to higher levels of sustainability or developing sustainably, and becoming more resilient - economically and ecologically.
While there are several sustainability and sustainable development frameworks, this framework explains how and why sustainable development objectives can change from community to community, and even for the same community over time. The conceptual definition of sustainability can be likened to the state achieved in Zone D, where it can be shown that members of the community under consideration have a high QOL and well-protected natural resources. In this zone, some communities may be operating at superior levels of sustainability compared with others; however, all the communities in this zone would be living satisfying lives within the carrying capacities of their environments. Sustainability for each community would therefore result in the same essential condition where a good quality of life is secured for all members of the community at an expense within the carrying capacity of the environment (based on the use of natural resources and assimilation of wastes). As movements from Zone A to D, B to D and C to D can all be viewed as sustainable development pathways, the priority issues of communities in these respective zones can also be different (e.g., quality of life versus preservation of natural assets). Therefore, communities in Zones A, B and C can have different sustainable development pathways to reach Zone D.
Sustainable transportation is generally used to refer to transportation that contributes to the sustainable development of the community that owns and uses the system. Various definitions adopted by different agencies tend to emphasize the elements that reflect their priorities as shown in Table 1-1, although most definitions embrace the triple bottom line factors of the economy, environment and social quality of life. Experience has shown that for transportation and other agencies to begin addressing sustainability issues, one of the first steps is to define sustainable transportation as it relates to their unique conditions.
|Ministry for the Environment, New Zealand http://www.mfe.govt.nz/issues/transport/sustainable/||Sustainable transport is about finding ways to move people, goods and information in ways that reduce its impact on the environment, economy and society. Some options include: (1) using transport modes that use energy more efficiently, such as walking or cycling, and public transport; (2) improving transport choice by increasing the quality of public transport, cycling and walking facilities, services and environments; (3) improving the efficiency of our car use, such as using more fuel efficient vehicles, driving more efficiently, avoiding cold starts, and car pooling; (4) using cleaner fuels and technologies; (5) using telecommunications to reduce or replace physical travel, such as tele-working or tele-shopping; (6) planning the layout of cities to bring people and their needs closer together, and to make cities more vibrant and walkable; and (7) developing policies that allow and promote these options, such as the New Zealand Transport Strategy.|
|Centre for Sustainable Transportation (Project funding: CST and the Government of Canada - Environment Canada and Transport Canada) (2003)||A sustainable transportation system is one that (1) Allows the basic access needs of individuals and societies to be met safely and in a manner consistent with human and ecosystem health, and with equity within and between generations; (2) Is affordable, operates efficiently, offers choice of transport mode, and supports a vibrant economy; (3) limits emissions and waste within the planet's ability to absorb them, minimizes consumption of nonrenewable resources, reuses and recycles its components, and minimizes the use of land and the production of noise.|
|Organization of Economic Cooperation and Development (Environment Directorate) (Project Funding: N/A) (1999)||Environmentally sustainable transportation is transportation that does not endanger public health or ecosystems and that meets needs for access consistent with (1) use of renewable resources at below their rates of regeneration and (2) use of non renewable resources below their rates of regeneration|
|PROSPECTS: Developing Sustainable Urban Land Use and Transport Strategies: Methodological Guidebook: Procedures for Recommending Optimal Sustainable Planning of European City Transport Systems (Project Funding: European Commission's Energy, Environment and Sustainable Development Programme) (2003)||A sustainable urban transport and land use system: (1) Provides access to goods and services in an efficient way for all inhabitants in the urban area; (2) protects the environment, cultural heritage and ecosystems for the present generation, and (3) does not endanger opportunities of future generations to reach at least the same welfare level as those living now, including the welfare they derive from their natural environment and cultural heritage.|
|The Sustainable Transportation Action Network (Sustran), The Urban Environmental Management Research Initiative (UEMRI), Global Development Research Center (GDRC)||Sustainable transportation concerns systems, policies, and technologies. It aims for the efficient transit of goods and services, and sustainable freight and delivery systems. The design of vehicle-free city planning, along with pedestrian and bicycle friendly design of neighborhoods is a critical aspect for grassroots activities, as are telework and teleconferencing. It is more about accessibility and mobility, than about 'transportation'.|
Just over half of DOT mission statements include sustainability principles, which is a significant increase from 2005 when around one-quarter reflected sustainability (4). While no two are identical, several address impacts on the economy, environment and social quality of life. However, only two DOTs actually use the term "sustainable", and each uses unique wording and combination of principles. It is also true that not all agencies with missions that incorporate elements of sustainability can point to formal initiatives for implementing them. At the same time, there are agencies that have formal initiatives and programs for addressing sustainability but have mission statements that do not say much or anything about sustainability. Table 1-2 shows DOT mission statements with elements of sustainability.
|Alabama||To provide a safe, efficient, environmentally sound intermodal transportation system for all users, especially the taxpayers of Alabama. To also facilitate economic and social development and prosperity through the efficient movement of people and goods and to facilitate intermodal connections within Alabama. ALDOT must also demand excellence in transportation and be involved in promoting adequate funding to promote and maintain Alabama's transportation infrastructure.|
|Arkansas||It is our mission to provide and maintain a safe, effective, and environmentally sound transportation system for the state.|
|Connecticut||To provide a safe and efficient intermodal transportation network that improves the quality of life and promotes economic vitality for the State and the region.|
|Delaware||To provide a safe, efficient, and environmentally sensitive transportation network that offers a variety of convenient, and cost-effective choices for the movement of people and goods.|
|Florida||Provide a safe transportation system that ensures the mobility of people and goods, enhances economic prosperity and preserves the quality of our environment and communities.|
|Georgia||Provides a safe, seamless and sustainable transportation system that supports Georgia's economy and is sensitive to its citizens and environment.|
|Hawaii||To provide a safe, efficient, accessible, and inter-modal transportation system that ensures the mobility of people and goods, and enhances and/or preserves economic prosperity and the quality of life|
|Iowa||Advocates and delivers transportation services that support the economic, environmental and social vitality of Iowa.|
|Illinois||To provide safe, cost-effective transportation for Illinois in ways that enhance quality of life, promote economic prosperity, and demonstrate respect for our environment.|
|Indiana||INDOT will plan, build, maintain, and operate a superior transportation system enhancing safety, mobility and economic growth.|
|Kentucky||To provide a safe, efficient, environmentally sound and fiscally responsible transportation system that delivers economic opportunity and enhances the quality of life in Kentucky.|
|Louisiana||To deliver transportation and public works systems that enhance quality of life and facilitate economic growth and recovery|
|Maine||To responsibly provide a safe, efficient,&reliable transportation system that supports economic opportunity&quality of life|
|Maryland||Efficiently provide mobility for our customers through a safe, well-maintained and attractive highway system that enhances Maryland's communities, economy and environment.|
|Michigan||Providing the highest quality integrated transportation services for economic benefit and improved quality of life|
|Mississippi||To provide a safe intermodal transportation network that is planned, designed, constructed and maintained in an effective, cost efficient, and environmentally sensitive manner.|
|Montana||To serve the public by providing a transportation system and services that emphasize quality, safety, cost effectiveness, economic vitality and sensitivity to the environment.|
|Nebraska||We provide and maintain, in cooperation with public and private organizations, a safe, efficient, affordable, environmentally compatible and coordinated statewide transportation system for the movement of people and goods.|
|New Hampshire||Transportation excellence enhancing the quality of life in New Hampshire. Transportation excellence in New Hampshire is fundamental to the state's sustainable economic development and land use, enhancing the environment, and preserving the unique character and quality of life.|
|New Mexico||The primary responsibility of the agency is to plan, build, and maintain a quality state-wide transportation network which will serve the social and economic interests of our citizens in a productive, cost-effective innovative manner.|
|New York||It is the mission of the New York State Department of Transportation to ensure our customers - those who live, work and travel in New York State -- have a safe, efficient, balanced and environmentally sound transportation system.|
|North Carolina||Connecting people and places in North Carolina - safely and efficiently, with accountability and environmental sensitivity.|
|Ohio||Moving Ohio into a Prosperous New World. Its meaning encompasses the multi modal, safe, efficient and reliable character identified in our last business plan mission statement. At the same time, it incorporates the realization that safety, economic development, green, innovative and accessible characteristics are additional drivers needed to achieve the prosperity that will assure Ohio's future competitiveness.|
|Oregon||To provide a safe, efficient transportation system that supports economic opportunity and livable communities for Oregonians.|
|Rhode Island||To maintain and provide a safe, efficient, environmentally, aesthetically and culturally sensitive intermodal transportation network that offers a variety of convenient, cost-effective mobility opportunities for people and the movement of goods supporting economic development and improved quality of life.|
|South Dakota||We provide a quality transportation system to satisfy diverse mobility needs in a cost effective manner while retaining concern for safety and the environment.|
|Tennessee||To plan, implement, maintain and manage an integrated transportation system for the movement of people and products, with emphasis on quality, safety, efficiency and the environment.|
|Vermont||To provide for the movement of people and commerce in a safe, reliable, cost-effective and environmentally responsible manner.|
|Virginia||To plan, deliver, operate and maintain a transportation system that is safe, enables easy movement of people and goods, enhances the economy and improves our quality of life.|
|West Virginia||To create and maintain for the people of West Virginia, the United States and the world a multi-modal and inter-modal transportation system that supports the safe, effective and efficient movement of people, information and goods that enhances the opportunity for people and communities to enjoy environmentally sensitive and economically sound development.|
Sustainable transportation - Transportation that promotes sustainable development.
Sustainable development - Development that meets the needs of the present without compromising the ability of future generations to meet their own needs (from World Commission on Environment and Development)
Sustainability - A set of environmental, economic and social conditions in which all of society has the capacity and opportunity to maintain and improve its quality of life indefinitely without degrading the quantity, quality or the availability of natural, economic and social resources (from American Society of Civil Engineers)
Climate Change - A statistically significant variation in either the mean state of the climate or its variability over an extended period, typically decades or longer, that can be attributed to either natural causes or human activity (from TRB Special Report 290)
NEPA - The National Environmental Policy Act (NEPA) requires federal agencies to integrate environmental values into their decision making processes by considering the environmental impacts of their proposed actions and reasonable alternatives to those actions. To meet NEPA requirements federal agencies, or agencies using federal funds, prepare a detailed statement known as an Environmental Impact Statement (EIS).
AASHTO: American Association of State Highway and Transportation Officials
ASCE: American Society of Civil Engineers
ASTRA: Assessment of Transport Strategies
BTS: Bureau of Transportation Statistics
Caltrans: California DOT
CBA: Cost-Benefit Analysis
CO: Carbon Monoxide
CSD: Context Sensitive Design
CSS: Context Sensitive Solutions
CTP: Common Transport Policy
DDOT: District of Columbia DOT
DOE: Department of Energy
DOT: Department of Transportation
ECMT: European Conference of Ministers of Transport
EIA: Energy Information Administration
EIA: Environmental Impact Assessment
EJ: Environmental Justice
EPA: Environmental Protection Agency
ESCOT: Economic Assessment of Sustainability Policies of Transport
EST: Environmentally Sustainable Transport
EU: European Union
FDOT: Florida DOT
FHWA: Federal Highways Administration
FMP: Framework Program
GHG: Greenhouse gas(es)
GIS: Geographic Information System
GreenLITES: Leadership in Transportation and Environmental Sustainability
HIA: Health Impact Assessment
HUD: Department of Housing and Urban Development
LCA: Life Cycle Assessment
LCCA: Life Cycle Cost Analysis
LEED: Leadership in Energy and Environmental Design
MCA: Multi-Criteria Analysis
MDSHA: Maryland State Highway Administration
MnDOT: Minnesota DOT
MoDOT: Missouri DOT
MPO: Metropolitan Planning Organization
NCHRP: National Cooperative Highway Research Program
NEPA: National Environmental Policy Act of 1969
NJDOT: New Jersey Department of Transportation
NOx: Nitrous Oxides
NYSDOT: New York State Department of Transportation
NZTS: New Zealand Transport Strategy
OECD: Organization for Economic Cooperation and Development
ODOT: Oregon Department of Transportation
PennDOT: Pennsylvania Department of Transportation
QOL: Quality of Life
SCS: Sustainable Communities Strategy
SEA: Strategic Environmental Assessment
SMP: System Management Pyramid
SSA: Strategic Sustainability Analysis
SSUT: Socially Sustainable Urban Transportation
T&DI: Transportation & Development Institute
TRB: Transportation Research Board
TxDOT: Texas Department of Transportation
UK: United Kingdom
USDOT: United States Department of Transportation
VIBAT: Visioning and Backcasting for Transport Policy
VMT: Vehicle miles traveled
VOC: Volatile Organic Compounds
VTrans: Vermont Department of Transportation
WSDOT: Washington State Department of Transportation