Abstract:

Reducing travel demand through urban planning practices has not been explicitly discussed in the past to reduce emission from vehicles in Asian cities. On the other hand, the modal structure change, energy intensity and fuel improvement have often been discussed as the centre of vehicle emission control. It is important to know that these three measures are rather short-term and independent issues, and reducing travel demand is a long-term, integrated one. Thus the research gives a new scope in dealing with emission reduction from transportation.

There are several studies which dealt with the relationship between urban form and travel demand reduction, and a number of case studies in different cities. Early kind is by Mitchell and Rapkin (1954) by "Urban Traffic: A function of land use". Kenworthy and Laube (2000) presented the connection between urban density and energy consumption of the dozens of world cities from United States, Australia, Europe and Asia. Researches by Frank and Pivo (1994), Schimek (1996), Crane and Crepeau (1998) and Cervero (2002) have hypothesized the strong association between higher density levels and lower automobile emissions, lower vehicle miles traveled (VMT), lower gasoline usage, lower rates of vehicle ownership and higher rates of transit usage.

In these studies, three aspects of urban forms comprising: density, land use mix and TND (traditional neighborhood design), have often been highlighted. Urban density and land use mix are the traits which Asian cities already possess (Newman and Kenworthy 1999, Lim 1999). In contrast, urban design such as human-scaled street designs, traffic calming, and street connectivity has not been actively introduced in Asia. This paper discusses how the City of Yokohama has worked on emission reduction from transport and policies on dense/land use mix and TND have the opportunity and barriers in current urban planning framework.

Presentation: http://www.cleanairnet.org/baq2006/1757/docs/SW10_2.ppt