Transportation's Role in Reducing U.S. Greenhouse Gas Emissions ...

Transportation's Role in Reducing U.S. Greenhouse Gas Emissions: Volume 1
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– Improve transportation system efficiency; and
– Reduce carbon-intensive travel activity.
The legislative mandate for the report focused on transportation system
efficiency and travel activity strategies. As such, the Department made a strong
effort to thoroughly cover these areas. The Department also took a holistic
approach, including consideration of vehicle technology and alternative fuels
strategies. This broad approach better addresses the topic of transportation and
climate change, given the important contribution of technology, the interactions
between strategies, and the recognition that Federal actions—such as pricing—
will often spur both technological and behavioral changes. Even so, due to fuel
economy and renewable fuel standard rulemakings, potential transportation
greenhouse gas reduction and cost-effectiveness estimates are not presented for
some vehicle and fuel technology strategies.
• Section 4—Cross-cutting Policies: Discusses policies that involve all four
strategies above.
– Federal transportation planning requirements and funding mechanisms can
play a role in shaping sustainable transportation programs that provide
mobility, while reducing greenhouse gas emissions. These cross-cutting
policies influence both system efficiency and travel activity.
– Carbon pricing through a cap and trade system, carbon tax, or a higher
motor fuels tax would provide incentives to consumers and businesses to
pursue all four strategies above; and
• Section 5—Policy Options: Discusses five key Federal policy options that can
reduce greenhouse gas emissions from transportation.
Further detail on this analysis is provided in Volume 2: Technical Report. Volume
2 contains detailed technical discussions of the four strategy groups that can
contribute to reducing the carbon footprint of the transportation sector. All
transportation sub-sectors are considered in this report, including on-road
vehicles, rail, aviation, and marine. Each set of strategies is evaluated based on a
set of factors including magnitude of GHG reduction; timing of impacts, cost, cobenefits
(such as fuel savings and air quality) implications for other DOT goals;
impacts on infrastructure financing; and feasibility and implementation
considerations. The benefits of the strategies in this report are based on limited
data and good faith assumptions. Numerical estimates contain substantial
uncertainties, as described in the methodology section. Each GHG reduction
strategy may have various positive (co-benefits) or negative impacts on other
factors as well. Potential tradeoffs and interdependencies when reducing GHG
emissions will need to be considered when developing balanced solutions.
Readers interested in the technical basis for the summary materials and policy
recommendations contained in Volume 1 are directed to Volume 2 for additional
background information.