A Study on the Medium-Term Effects of Regional Travel Speed on CO2 Emissions of Passenger Cars

Abstract

This paper examines whether higher regional travel speed lead to lower regional CO2 emissions of passenger cars. Some action plans toward low carbon transport contain new road construction plans, because it was often said that the improvement of regional travel speed contribute to reduction of CO2 emission factor enough to reduce regional CO2 emissions in spite of the growth of traffic volume in the short term. This study estimates regional CO2 emissions considering travel speed with master data of origin destination survey of national road census in 1999 and 2005. It shows that lower regional travel speed reflects shorter trips and smaller passenger car usages in higher density areas and tends to make CO2 emissions smaller in the medium term.