Editorial introduction

Abstract

Many factors can contribute to sustainable transport, for instance green/greener transport modes, spatial design and connectivity among transport infrastructure, land use or urban form, travel behaviour, etc. In the first paper of this issue, Chen and Felkner (2020) conduct an extensive review on the relationship between sustainable transport and urban form, and point out that many researchers have only discussed relationships between sustainable transport with individual elements of urban forms, without considering the interrelationships among the elements of urban forms such as population density, concentration within the urban-rural context, and land use mix. To fill this gap, the authors perform robust regressions on sustainable transport indicators and urban form elements using the case of the U.S. State of Florida. They found that the interaction effects among urban form elements show in a "threshold, negative-to-positive" synergy, which implies that certain expected effects from urban form elements on sustainable transport outcomes are conditional depending on levels of other urban form elements. Although the paper was not able to discuss interaction effects among all the elements, the argument is justified, the analysis is acceptable and the paper raised a research question that needs wider attention.The second paper by Pan, Zheng, and Wang (2020) takes a disaggregated approach. The authors conduct a survey of 1245 people living in 27 residential compounds in Shanghai. The attributes included individual socioeconomic characteristics such as age, gender, living space, and car ownership; accessibility to public transit such as metro and bus stations; and built environment of the residential compounds as well as that of their working places such as parking space, schools, supermarkets, and hospitals. The transport modes of each person's commute were also surveyed and the CO 2 emissions of each mode were added up to compute the total emissions of the trip. Many insightful findings are reported through an analysis of the relationships between commuting CO 2 emissions and the aforementioned attributes, which support or revise the results of previous literature. One new finding deserves more policy-maker attention, which is that the top 20% of commuters in Shanghai were responsible for 80% of the total commuting CO 2 emissions, and many rich people do not use low-carbon urban rail despite living in locations near rail stations.