Estimating the increase in emissions associated with induced travel from road capacity expansions and traffic flow improvement projects
All authors:
Noland, R.
Publication year: 2006
Published in:
VREF, Smaller Project 2003-07
Research theme: Environment and Climate Change, Policy and Planning
road schemes, road space, availability, induced demand, emissions
Final Report
The key objective of the proposed research is to determine whether road schemes that increase the availability of road space or which smooth the flow of traffic results in increased vehicle pollution. Economic theory has found that increases in road space and the consequent decreases in travel time will tend to increase total vehicular travel. This is known as induced demand, a subject that has been debated by transport planners for decades. Recent research research has led to a growing consensus on the inducing effects of new road capacity (Noland & Lem, 2002). The net impacts on vehicle pollution have largely been a matter of conjecture with some arguing that policies to reduce congestion (by adding more road space) will reduce pollution. This occurs due to reductions in stop and go traffic and the smoothing of total vehicle flow. These questions, while frequently debated amongst transport and environmental planners, have yet to be clearly analyzed using adequate methodologies. This project uses a combination of simulation and statistical methodologies to evaluate the overall strategic policy question of how changes in available road capacity effects vehicle emissions.
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The VREF invites Sub-Saharan based researchers with expertise on sustainable and equitable
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