Transportation Ecoefficiency: Quantitative Measurement of Urban Transportation Systems with Readily Available Data
提出了一个利用通勤方式和人口密度等易获取数据计算的交通生态效率指标，并用它分析了美国和英国大都市区1980-2008年和1981-2001年的变化趋势，发现两国生态效率都在下降。
In this study, the concept of transportation ecoefficiency (TE) is described, and it is argued that this concept offers coherence to theoretical discussions of the environmental impact of transportation. A TE measure using readily available data is proposed, with four components: (1) percentage of commuters driving to work; (2) percentage of commuters taking public transit; (3) percentage of commuters walking or riding a bicycle; and (4) population density. A confirmatory factor analysis suggests that these components are useful for measuring TE and consistent in their relationships over time. This TE index is used to analyze TE in metropolitan areas in the United States (1980–2008) and in the United Kingdom (1981–2001): TE is decreasing in both countries despite very different starting points, with worrisome implications for climate change and other transportation-related environmental impacts. The paper concludes with a discussion of some uses for the TE metric in empirical research and planning practice, and how the concept could enhance the literature on transportation and the environment.