In this century, surface transport systems have become increasingly
automobile dependent. Recent research challenges the
assumption that increased automobile travel is necessarily good for
an economy or society. Beyond a certain level, automobile
dependency may impose more costs than benefits.
Highway advocates support increased construction of roadways,
increased parking requirements, and low automobile user charges.
They point out that motor vehicle travel is growing due to
increased population, wealth and suburban lifestyles, resulting in
increased traffic congestion. They argue that failing to expand
roadway and parking capacity, and efforts to constrain motor
vehicle use, contradict consumer preferences, stifle economic
growth, and reduce personal freedom. They cite the general failure
of public transit in the U.S. to attract new riders as evidence
that highways are the most cost effective transportation
investment. Highway advocates often argue that fuel taxes and other
motor vehicle user charges should be dedicated to roadway
improvements.
Transportation Demand Management (TDM) advocates support the
development of a more diverse transport system. They recommend
investing in travel alternatives and using a variety of
Transportation Demand Management strategies, including higher user
charges, to curb automobile traffic growth. They point to the high
economic, social and environmental costs associated with motor
vehicle use, and market distortions that result in excessive
automobile travel, as evidence that increased motor vehicle use is
overall harmful to communities. They argue that creating a more
diversified transportation system is the most effective way to
address traffic congestion, meet economic and social needs, support
economic development, and protect the environment. They cite the
tendency of "generated traffic" to fill new highway capacity, and
the success of public transit and bicycle programs in some
communities, as evidence that such alternatives are the most cost
effective transportation investments. TDM advocates often argue
that fuel taxes and other automobile user charges should be spent
on travel alternatives, since motorists benefit indirectly from
such investments, and because motor vehicle use does not pay its
full costs.
Aide Memoire
"AUTOMOBILE DEPENDENCY: TOO MUCH OF A GOOD THING?
Debating the Optimal Level of Automobile Use"
Double Session on the Economic and Social Impacts of Automobile
Dependency Transportation Research Board 1999 Annual Meeting
Monday, January 11, 1998 8 a.m. to 12 noon
International East Room, Hilton, Washington DC
