The relationship between the characteristics of transportation energy consumption and urban form

In this paper, we analyze the relationship between the characteristics of transportation energy consumption and urban form elements that were actively argued along with Environmentally Sound and Sustainable Development (ESSD). This paper can be divided into two parts: an examination of the theories and a practical analysis of domestic, small-, and medium-sized cities. Firstly, in the examination of theories, we surveyed the arguments about the sustainable urban form. Secondly, we made some hypotheses about the relationships between transportation energy consumption, city size, density, and center distribution pattern. Thirdly, we tested those hypotheses and examined the suitability of policies for each alternative for small- and medium-sized cities in Korea. The main themes in this paper are as follows. Firstly, how does the city size, density, etc. affect the transportation energy consumption? Secondly, in an overcrowded Korean situation, which alternative is the more suitable sustainable urban form from the point of transportation energy consumption, i.e., concentration or decentralized concentration? Thirdly, we examined the argument that a densely centralized development can reduce the need for travel, increase the transit use, and decrease automobile use. From the results of the analysis, we found that as the population increases, transportation energy represented by yearly gasoline consumption per automobile and the average yearly energy consumption as a result of surface transportation per 1,000 persons tends to decrease. Further, if the degree of city's concentration represented by Gini coefficient is high, energy efficiency tends to decrease. Besides, the influential factors on the transportation energy consumption among the indicators of urban form could be road ratio and density. Whereas the road ratio is not related to the transportation energy consumption, road density is. From the analyzed results, we can deduce planning implications concerned with Korean cities. Firstly, Korean cities are already highly centralized so a decentralization policy should be carried out to increase transportation energy efficiency. In any case, in the case of high-density cities, multinuclei cities are better than mononuclear ones. Further, to increase the transportation energy efficiency, policies for high road densities through the construction of new roads in spite of narrow road widths are more effective than those for high road ratio-widening existing roads.