Chapter 1 - Caltrans - State of California

Chapter 3 Comments and Coordination
same. This increase in emissions would be offset due to increases in speeds and
reductions in congestion (which are associated with lower MSAT emissions). Regardless
of alternative chosen, emissions would likely be lower than present levels in the design
year as a result of EPA’s and California’s control programs that are projected to reduce
MSAT emissions by at least 57 to 87% between 2000 and 2020. Local conditions may
differ from these national projections in terms of fleet mix and turnover, VMT growth
rates, and local control measures. However, the magnitude of the EPA-projected
reductions is so great (even after accounting for VMT growth) that MSAT emissions in
the study area are likely to be lower in the future in nearly all cases when compared to the
present level.
Both 2016 and 2036 result in similar trends that indicate a decrease in MSAT emissions
for all BUILD Alternatives when compared to the existing MSAT emissions. Because
the proposed project is not expected to attract rerouted trips from elsewhere in the
transportation network, estimated VMT for each of the BUILD Alternatives are expected
to be the same MINIMUM BUILD and FULL BUILD have the same overall (mainline
plus HOV) MSAT emissions. As shown in Tables 2.2-5 and 2.2-6, all BUILD emissions
are slightly higher than the NO BUILD MSAT emissions although the VMT stayed the
same. This increase in emissions would be offset due to increases in speeds and
reductions in congestion (which are associated with lower MSAT emissions). Regardless
of alternative chosen, emissions would likely be lower than present levels in the design
year as a result of EPA’s and California’s control programs that are projected to reduce
MSAT emissions by at least 57 to 87% between 2000 and 2020. Local conditions may
differ from these national projections in terms of fleet mix and turnover, VMT growth
rates, and local control measures. However, the magnitude of the EPA-projected
reductions is so great (even after accounting for VMT growth) that MSAT emissions in
the study area are likely to be lower in the future in nearly all cases when compared to the
present level.
The additional travel lanes proposed as part of the project alternatives would have the
effect of moving some traffic closer to nearby homes and/or businesses; therefore, under
BUILD alternatives, there may be localized areas where ambient concentrations of
MSATs could be higher under certain BUILD alternatives than the NO BUILD
alternative. The CARB’s “Air Quality and Land Use Handbook” identifies the following
land uses as particularly sensitive to MSATs: residential areas, schools, hospitals and
other health care facilities, day care and other child care facilities, and parks and
playgrounds. However, as discussed above, the magnitude and the duration of these
potential increases compared to the NO BUILD alternative cannot be accurately
IS/EA VEN-SB US101 HOV Project 155