Comprehensive Evaluation Framework for Climate Change Analysis in Transportation

Focus Area

Climate Change


Air Quality, Environmental Process







Research Idea Scope

The transportation sector is vital to the economy of the United States. It provides the critical links between industries and to their customers and it is the network for individual mobility. It is also a primary contributor to greenhouse gas (GHG) emissions. The transportation sector currently accounts for about 30% of total US GHG emissions, and this is expected to grow in the future as population and economic growth coupled with GHG emissions reductions in other sectors (e.g. electric power, housing, and industrial) will focus concern on all modes of the transportation sector.
All current motorized modes of transportation rely on burning petroleum fuels for propulsion. As populations grow and economies expand, the demand for transportation, and thus petroleum, also grows. This growth in transportation activity will increase GHG emissions without changes in modes, fuels and other decisions. In order to slow or reverse this trend, public policy has been addressing three components of the link between transportation and GHG emissions.   The three components are:

Efficiency (Vehicles) – this refers to the rate at which energy is consumed by vehicles. This includes, for each transportation mode, both the vehicle or person miles per gallon and the operating characteristics that affect the actual amount of fuel consumed during on and off road use. Therefore, mitigation options include items ranging from new vehicle technology improvement (CAFE) to transportation systems management that improves vehicle efficiency by reducing congestion.
Carbon Content (Fuels) – this refers to the fuel source for each mode and the amount of carbon released in the combustion process. It includes current conventional fuels, improved conventional fuels and alternative fuels such as alcohol, natural gas, propane, electric power and hydrogen.
Activity (Travel) – this refers to the use of all vehicles to provide transportation service. It includes programs that discourage the use of vehicles that use high carbon fuels, promotes transportation alternatives and encourages increases in vehicle occupancy rates. This area also includes changes in land use planning that leads to a lower reliance on low energy efficiency vehicles for transportation.
Options in all three areas may be needed to achieve the stated GHG reduction goals contained in Climate Change Action Plans now adopted by about half the states and numerous regional and local government entities. It is remains unclear which options will be supported by the public and their elected representatives. The CAFÉ standards to improve fuel efficiency seem popular, but continued vehicle efficiency improvements will require some modification of consumer’s expectations for new vehicles. 
At the same time, government and industry analysts are evaluating options to minimize the adverse impact of expected climatological change such as sea level rise and severe storm events. Trade-offs between adaptation and mitigation policies must be understood and consistent analytic methods will need to be applied to correctly inform public decision making.
The transportation sector has sought to apply uniform standards for economic analysis of transportation projects and programs across states. One effort was the AASHTO sponsored development of a guidebook and software for the application of economic analysis in transportation programs. The so called AASHTO Red Book, “A Manual of User Benefit Analysis for Highways, 2nd Edition” was developed by a previous NCHRP Project #02-23. One possibility for the current study is to produce an addendum to the Red Book that would serve as a key reference source for the application of economic analysis to climate change mitigation and adaptation evaluation.
The objective of this research is to identify and explore the methods currently employed to evaluate GHG emissions mitigation and adaptation options. From this research, the study team will develop a set of guidelines and methods for economic analysis of transportation policies and programs that address climate change. The research should address the following questions:
·        How have the federal government, state and local governments, non-profit organizations and the private sector evaluated public policy and program actions in the transportation sector to mitigate the impacts and adapt to changing conditions brought about by climate change?
·        How have policy and program actions in other sectors been evaluated and are these techniques equivalent to those identified in the transportation sector?
·        What data is currently available to carry out these analyses and what new data may be required for a full and comprehensive analysis? Who should be responsible for collecting and making these data available to all?
·        What level of economic analysis, including benefit/cost, micro and macro economic impact, cost effectiveness and other techniques are appropriate?
·        What analysis is required to address price or market instruments, such as cap and trade or efficient pricing strategies?
Transportation analysts should be able to look to a common reference for analytic methods to evaluate these transportation responses to GHG emissions and climate change. These methods should reflect the state of the science in policy and program analysis and be accessible to all and reproducible. The range of analysis should cover all modes including non-motorized, all traditional forms of economic analysis, both internalized and external costs and indirect impacts such as those identified from land use.
Related Work
Selected related work includes: NAS, TRB and National Cooperative Research Program reports on climate change and transportation studies; National Surface Transportation Policy Commission Report; AASHTO Red Book; USDOT/USGS Gulf Coast Climate Study; and, reports by EPA , state, regional and local agencies. Studies sponsored by non-profit organizations such as the Urban Land Institute’s “Moving Cooler” or private sector studies such as the McKinsey & Company study “Pathways to a Low Carbon Economy” also provide additional data and methods.
The research would inform on-going policy discussions such as:
·        What are the likely economic costs to government, industry and households from the transportation policies under consideration to mitigate and adapt to climate change?
·        What is the appropriate role and responsibility of the public sector at all levels of government to provide transparent and supportable economic analysis of transportation policies and programs to mitigate and adapt to climate change? Can we expect such analysis to be uniform at all levels of government and across all states?
·        How should federal transportation programs and agencies—through the upcoming surface transportation, energy and climate change legislation as well as through other national or state transportation programs and policies—be charged with conducting comprehensive analysis of all proposed climate change policies and programs that impact transportation of people and goods?

Phase I – $450,000 literature review, workshop, development of methods. Phase II – $200,000 development of guidebook and software for climate change transportation analysis

Urgency and Payoff

Findings will be implemented as guidelines for the implementation of climate change action plans by federal, state, and local agencies.
EffectivenessThe research will shape understanding of the issues and opportunities facing transportation analysts as they provide critical information to decision makers and the public about potential changes in the delivery of transportation infrastructure and services. This analysis and guidebook will form part of a critical set of literature that will shape the nation’s response to climate change, with broad and far-reaching societal impacts.

Suggested By

RNS. Sponsoring Committee: A0020T, Special Task Force on Climate Change and Energy Source Info: Special Task Force on Climate Change & Energy January 2010 Workshop