| The main objective of this study is to determine if some functional relationships between urban form and transportation energy consumption could be identified. Toward this objective, a land use and transportation simulation model, called MOD3, and the UFSTAT/UFGRAF spatial analysis software, which calculates and displays several urban form measures, are used to produce a consistent and comparable set of transportation energy consumption and urban form measures. Eighteen different hypothetical but realistic cities are designed and simulated. The travel and energy consumption patterns and urban form of these cities are defined in quantitative terms using these two sets of measures. Regression models are used to test the hypothesis that transportation energy consumption is associated with various urban form measures. The regression results produced several strong relationships between the two types of measures.;Three major findings are as follows. First, the urban form measures used are found to be useful for defining the spatial characteristics of a city, and these measures clearly describe the degree of concentration/dispersion and the shape of the urban form. Second, most of the urban form measures are highly correlated with the transportation energy consumption measure. This indicates that more compact and centralized population and employment distributions, higher levels of accessibility to the city center, and higher central population densities are associated with lower levels of transportation energy consumption. Third, some polynucleated urban forms simulated in this study are found to be more transportation energy-efficient than some concentrated urban forms, although the former are more spatially dispersed, less accessible and less dense in the CBD than the latter. A major trade-off between energy savings and congestion exists which suggests that the polynucleated urban form may be the best way to compromise between conflicting energy efficiency and congestion minimization objectives. |
