Executive Summary
The risks posed by climate change and the dependence on imported petroleum are among the most challenging problems facing the United States. Many state and national policy makers are embracing proposals to reduce total greenhouse gas (GHG) emissions by 50 to 80 percent below current levels by 2050 and to reduce energy consumption by the transportation sector.
Transportation, which depends on petroleum for 97 percent of its fuel, is a major contributor to both climate change and energy dependence. It accounts for 28 percent of U.S. GHG emissions and consumes twice as much petroleum as the United States produces annually. Passenger and freight vehicles using surface transportation modes account for about 88 percent of transportation carbon dioxide emissions and for a comparable share of energy consumption.
Projections of the impact of policies already in place to improve fuel economy and introduce alternative fuels suggest that total transportation GHG emissions by 2030 would be about the same as currently. The substantial improvements in vehicle fuel economy that will occur and other improvements will roughly offset the effects of expected population and economic growth on demand. As a result, additional reductions from the transportation sector are being sought in proposed legislation through policies that would reduce demand for the most fuel-intensive modes.
Transportation contributes significantly to total GHGs and energy dependence, but it also contributes to economic and social well-being. Careful selection of policies to reduce or shift demand will help to avoid or minimize losses to the economy and society. Unfortunately, the effec-
tiveness, costs, feasibility, and acceptability of various policies to mitigate transportation’s GHG emissions and energy consumption are not well understood.
Also not well understood are the policies and practices that should be considered for adapting the transportation system to changes in precipitation, flooding, storm surges, and wind loadings that are likely to occur in the future as climate changes. The cost of adapting infrastructure is high, as is the uncertainty about the timing, magnitude, and location of the risks.
Federal, state, and local policy makers need informed guidance about the effectiveness costs, feasibility, and acceptability of transportation mitigation and adaptation strategies. The committee that prepared this report recommends making a modest investment of $40 million to $45 million annually that would be used to develop the best available guidance quickly on the basis of existing information and then to improve that guidance over time as new research is completed (Table ES-1). Such an investment represents about 9 percent of current U.S. Department of Transportation research spending on surface modes. Because of the importance of making policy choices that produce the most benefit for the least harm, such investments could pay substantial long-term dividends. The committee’s research cost estimate is an approximation meant to give Congress a sense of the level of investment needed.
TABLE ES-1 Estimated Cost of Mitigation and Adaptation Research Programs ($ millions)
Program |
6-Year Total |
Annual Average |
Mitigationa |
|
|
Guidance and outreach |
60.0 |
10 |
Fundamental research |
130.0 |
21.7 |
Subtotal |
190.0 |
31.7 |
Adaptation |
|
|
Research |
60.0 |
10 |
Total |
250.0 |
41.7 |
aThe mitigation research cost estimate does not include the cost of collecting travel data for research and improved modeling practice purposes (Appendix B) or the cost of a mileage charging demonstration program (Appendix A). |
The topics suggested for research in the report are preliminary and should be refined by convening expert and practitioner stakeholders early in the program to develop more detailed plans and more refined estimates of investment needs over the longer term.
For such research to be most effective, it should be guided by the following principles: the topics investigated should be directly relevant to the needs of federal, state, and local transportation policy makers; funding should be awarded on the basis of open competition and merit review of proposals by peers; and results should be evaluated by expert and practitioner stakeholders. Program managers should have the flexibility to shift areas of investment as knowledge is developed. Such a program should also be evaluated on an ongoing basis by an independent group that would report directly to Congress.
One of the most effective mitigation strategies would be to tax or charge for use of the system in ways that more fully reflect the economic, social, and environmental costs of its use. Charging for mileage traveled on all roads could make this possible in the future and could supplement or replace taxes on fuels that currently generate revenues for highway and transit infrastructure. Fuel taxes have become unreliable revenue generators, and their unreliability will grow as fuel economy improves. Mileage charging shows promise but is controversial because of concerns about privacy, equity, and administrative costs. The committee joins other groups—including two congressional commissions—that have called for investing in an aggressive demonstration program to test alternative concepts and address these concerns. The total cost would probably be in the $70 million to $100 million range over a multiyear period (see Appendix A).
Research into and analysis of cost-effective GHG emission-reduction strategies will depend on quality data. The passenger and freight travel data available for national-level estimates are useful, but they are too crude to guide the detailed analysis and planning required to inform decisions about the best strategies at the state and local levels. Much of the needed data could be used for statewide and metropolitan area planning, could improve compliance with other environmental policy goals, and would be essential if performance standards are included in surface transportation reauthorization. The committee recommends that Congress
authorize funding for the collection of data adequate to meet the needs of federal, state, and local governments as they analyze options and plan for mitigation strategies.
Climate change and energy dependence will continue to be significant problems for decades to come. Transportation’s contributions to these problems must be addressed, but choosing the wrong policies could impose significant costs without ensuring the intended effects. The research programs identified in this report represent the topics that will be of greatest importance for informing the best choices in coming years.