Research on the causal relationship between urban density, travel behaviours, and transportation energy consumption by economic level

Abstract

As motorization has progressed around the world, the scope of personal activity is widening due to private-motorized modes (PMM). And due to the increase in PMM, the degree of suburbanization has also increased, resulting in higher energy consumption for transportation as well as global warming. Many studies including that of Newman and Kenworthy have focused on the relationship between urban density and transportation energy consumption. However, the studies were in general focused on a pool of transportation data limited to one country or continent. This geological limitation restrains researchers from gaining insight into different transportation characters as well as a city's economic development status. Therefore, this research was conducted to generate a database of transportation energy consumption by PMM based on person trip data from 119 metropolitan areas in 39 countries. Considering the difference in economic levels of cities around the world, a discriminant analysis was conducted to evaluate the relationship between urban density and transportation characteristics. Based on the results of the analysis, we examined the correlation between urban density and transportation energy consumption by economic level. The analysis showed that the correlation between urban density and transportation energy consumption differs by the city's economic level. Additionally, the more the economic development, the clearer the correlation between urban density and travel behaviours becomes.