The MOBILE5 model, widely used in evaluating the
impacts of transportation investments on air quality, is
insensitive to the effects of acceleration or deceleration
on emissions and thus cannot model the effects of
improvements such as a reduction in grade. The
problem with MOBILE is that it uses average speed as
the only variable to represent driving dynamics which
are strongly related to vehicle emissions. These
dynamics are often not properly characterized by
average speed. The objective of this study was to
develop emission models that take
acceleration/deceleration into account.