The burning of fossil fuels to power transportation is one of the main sources of growth in greenhouse gas (GHG) concentrations in the atmosphere. Petroleum-based fuels used by almost all cars, trucks, ships, and aircraft account for 97 percent of energy use in the transportation sector (Davis et al. 2009, Table 2-5). Collectively, the U.S. transportation modes produce about 28 percent of the GHGs emitted from the country each year (Davis et al. 2009, Table 11-4). Moreover, transportation carbon dioxide emissions (the main GHG emissions from transportation) are growing faster than is the U.S. economy as a whole (Davis et al. 2009, Table 11-5).
In addition, the transportation sector’s dependence on oil contributes to U.S. reliance on petroleum from exporting regions of the world. Transportation in the United States alone consumes more than twice the petroleum that is produced domestically (Davis et al. 2009, Tables 1-11 and 1-16). U.S. reliance on foreign sources of petroleum contributes significantly to the U.S. balance of payments deficit and raises security challenges.
In 2009, prospects were heightened for significant federal action to reduce energy imports and respond to climate change when a new Congress and a new administration arrived in Washington. At the time of this writing, October 2009, legislation had already passed the U.S. House of Representatives that would limit carbon emissions through a carbon cap-and-trade proposal and impose additional constraints on transportation to reduce its large and growing share of national GHG emissions.1 A bill
with similar provisions was unveiled by the chairman of the Senate Environment and Public Works Committee, Barbara Boxer, and Senator John Kerry in October 2009. Earlier, in May 2009, the Obama administration brokered a compromise between the automobile industry and California over proposed state regulation of motor vehicle fuel economy standards by agreeing to accelerate achievement of increased fuel economy standards enacted by Congress as recently as 2007 from 2020 to 2016. Yet to come is the reauthorization of surface transportation programs, which affects infrastructure investment policies as well as policies affecting the use of the infrastructure. In June 2009, Chairman Oberstar and the leadership of the Transportation and Infrastructure Committee, U.S. House of Representatives, unveiled a sweeping proposal for reauthorizing transportation legislation, which included significant linkages to the climate change legislation already passed in the House.
The House climate bill, the proposed climate bill of Chairman Boxer and Senator Kerry, and the proposed surface transportation reauthorization legislation of Chairman Oberstar would require extensive new planning processes under which officials at the federal, state, and local levels would set targets for transportation GHG reduction and then develop plans and programs to achieve them. The achievement of these goals would be enforced through provisions in the Clean Air Act that allow withholding of federal aid for noncompliance (Holt 2009, 56) and possibly through citizen lawsuits.2
States have also been active in responding to climate change. About three dozen states have created climate action plans, of which about half have set specific GHG reduction targets, typically 75 to 85 percent below current levels by 2050. Few states have transportation-specific targets; rather, the statewide targets are meant to inform the planning of state and metropolitan planning agencies. California, however, has been at the forefront of state action. The state has set aggressive GHG emission stan-
The transportation planning and GHG target-setting provisions are in a title of the Waxman–Markey climate bill that amends the Clean Air Act. Metropolitan planning organizations and others have raised concerns about whether these new provisions would be subject to citizen lawsuits. [See letter to Chairman Waxman from the Association of Metropolitan Planning Organizations and others dated June 1, 2009 (http://www.ampo.org/assets/library/209_amponadoaashtoclimatelett.pdf, accessed Aug. 7, 2009).]
dards for light-duty vehicles and has required the California Air Resources Board to establish transportation GHG reduction targets for each of the state’s 18 metropolitan planning organizations. In September 2008 California adopted the first state law to include land use policies designed to curb sprawl and reduce automobile travel as part of a strategy to reduce state GHG emissions.
Most current federal transportation policies and programs that attempt to reduce emissions focus on vehicles and fuels, which, as explained in the Preface, are not within the committee’s charge and for which research recommendations are not made in this report. New policies being contemplated, referred to as mitigation policies, influence the use of vehicles through strategies that raise the cost of using, or regulate more heavily the use of, higher energy-consuming and GHG-emitting types (automobiles, trucks, and aircraft) and encourage shifts to more energy-efficient modes (transit, rail, and water). State climate action plans having a transportation component drive state mitigation policies in the same direction. The Obama administration’s strong commitment to investment in high-speed passenger rail is also considered a mitigation policy.
Although mitigation policies are most prominent, it is also important to adapt to climate change. Adaptation refers to actions taken to alleviate, reduce, or eliminate the impacts of changes in climate. A recent National Research Council report (TRB 2008) made a compelling case for the need to consider adaptation of transportation infrastructure and operations in response to changing climate and weather conditions.
Both mitigation and adaptation policies will be set at all levels of government. Transportation infrastructure, particularly highways, transit, ports, and many short line railroads, are owned and operated by governments. Roads and highways are owned and operated by the 50 states and tens of thousands of counties and cities. Transit systems are owned and operated by hundreds of cities, counties, and special authorities. Many states own short line railroads. Although some port terminals are private, most port properties are owned and managed in the public sector. Whereas the federal government typically regulates vehicles and fuels at the national level, governments at all levels set policies affecting the use of infrastructure. Moreover, the land use decisions that determine the spatial arrangement of the built environment, which, in turn, establishes
the distances between origins and destinations and the amount of travel, are set by tens of thousands of local governments.
Mitigation and adaptation policies cover a broad range. This report discusses policies with regard to charging for the use of infrastructure, setting tax rates to reflect the full societal cost of infrastructure use, setting regulations that directly and indirectly affect the choices of modes, investing in new infrastructure, regulating land use, and others. Also covered briefly are strategies to reduce energy consumption and GHG emissions through more efficient management of surface transportation infrastructure and through less energy-intensive construction and maintenance practices. Adaptation strategies include investment in protection (berms and levees); the replacement, movement, and upgrading of infrastructure; revision of standards and operating practices; and improvement in the monitoring of infrastructure performance under climate change–induced stresses.
It is not always clear which choices will result in desired effects, what the costs and benefits might be, what the implications are for equity, or which choices will provide the most benefit for the least cost. Policies affecting transportation have both economic and social consequences. Travel is an integral part of the economy and lifestyles of the nation’s citizens. Informing the choices facing federal, state, and local policy makers is the role of transportation research and policy analysis; this report addresses the research needed to make these choices as well informed as possible.
Chapter 2 provides an overview of existing federal transportation and transportation-related research programs addressing climate change and energy. It provides a description of the scale and scope of these programs. Chapter 3 addresses gaps in knowledge about transportation mitigation strategies and identifies areas for research. Chapter 4 addresses surface transportation adaptation knowledge gaps and areas for research. Chapter 5 summarizes the main research initiatives identified in Chapters 3 and 4 and the level of investment needed, describes criteria for how the research programs should be managed to be most effective, and provides
a summary of the report. Research and demonstration strategies to address mileage charging fees or taxes as a supplement to the motor fuel tax are reviewed in Appendix A. Critical travel data gaps and the potential cost of providing the needed data are described in Appendix B.
TRB Transportation Research Board
Davis, S. C., S. W. Diegel, and R. G. Boundy. 2009. Transportation Energy Data Book, 28th ed. ORNL-6984. Prepared by Oak Ridge National Laboratory for the U.S. Department of Energy, Washington, D.C. http://www-cta.ornl.gov/data/Index.shtml. Accessed Sept. 28, 2009.
Holt, M. 2009. Greenhouse Gas Legislation: Summary and Analysis of H.R. 2454 as Passed by the House of Representatives. R40643. Congressional Research Service, Washington, D.C.
TRB. 2008. Special Report 290: Potential Impacts of Climate Change on U.S. Transportation. National Academies, Washington, D.C.