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

3.11 SUMMARY OF FINDINGS
Transportation's Role in Reducing U.S. Greenhouse Gas Emissions: Volume 1
Tables 3.5—3.8 present a consolidated overview of GHG reduction strategies,
summarizing a wide range of specific information. The table includes the
following information for most strategies:
• Key Deployment Assumptions—Key assumptions about the strategy that
affect the magnitude of results.
• Effectiveness:
− Percent GHG Reduction—Percent reduction in GHG emissions from
baseline, for:
° Transportation Sector—Reduction as a percentage of total
transportation sector baseline emissions (based on Annual Energy
Outlook March 2009 Reference case) in 2030 (2,171 million metric tons
carbon dioxide equivalent, or mmt CO2e).
° Relevant Subsector(s)—Relevant transportation subsector(s)—lightduty
vehicle (LDV), heavy-duty vehicle (HDV), and on-road vehicles,
rail, marine, and aircraft—that strategy affects and percentage
reductions for this subsector.
− Absolute GHG Reduction—Absolute reduction in year 2030 or 2050,
expressed in million metric tons CO2e; range of values (lower/upper)
indicated when findings differ. Values for 2050 are shown only if
significantly different than for 2030. “N/A” signifies that values may be
significantly different in 2050 than 2030, but were not modeled in this
timeframe.
− Timing of Benefits—If the strategy is implemented today, this is a
projection of how long it would take to achieve the reductions noted.
Three ranges: i) Short—most benefits can be achieved within five years;
(ii) Mid—most benefits achieved within 5 to 20 years; (iii) Long—most
benefits not achieved for at least 20 years.
• Cost Effectiveness—Expressed in $/metric ton CO2e; range of values
(lower/upper) indicated when findings differ. The cost-effectiveness
estimates should be read with caution because they reflect monetary costs
only. They do not reflect other very significant benefits or disbenefits to
consumers such as travel time impacts, utility of foregone trips, health
benefits, air quality impacts, and increased or decreased accessibility or
mobility. Taxes, fees, and rebates are not included in cost-effectiveness
calculations, since they are regarded as a transfer payment (from the private
sector to the public sector). However, the imposition of taxes, fees, and
rebates may create welfare changes that are difficult to monetize but
nonetheless represent a real cost or benefit to consumers. The two types of
cost effectiveness cited are:
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