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

Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
GHG reductions are based on the differences in VMT for individuals living in areas of 4000
ppsm or more versus individuals living in lower density areas, according to the 2001
National Household Travel Survey (NHTS), and modeled by the Center for Urban
Transportation Research (CUTR). As such, the proxy only incorporates the current
difference in VMT between different density levels and does not incorporate additional
policies that could be pursued such as mixing land uses.
The analysis only considers new development in metropolitan areas. It does not assume
any changes in rural areas. The pie charts in Figure 5.6 compare the distribution of the
U.S. metropolitan area population in 2030 and 2050 under the most aggressive Moving
Cooler scenario to the year 2000 actual population distribution.
Figure 5.6 Distribution of U.S. Urban Population
New development in metropolitan areas at greater than 5 units per residential acre could
take the form of small lot single family homes, townhomes, apartments, condominiums, or
combinations of these with large lot single family homes. The photographs in Figure 5.7
and 5.8 show examples of housing at various numbers of units per acre.
Vehicle miles traveled (VMT) reductions under the scenarios are calculated based on a
VMT model developed by the Center for Urban Transportation Research (CUTR) at the
University of South Florida. The base data for the model is from the 2001 National
Household Travel Survey (NHTS). The VMT reductions in the model are shown in the
table below. As shown, those in areas with greater than 5 dwelling units per acre travel
28% fewer miles than those in areas with less than 0.6 dwelling units per acre.
5-58