A number of studies have provided evidence of the positive role of physical (urban) planning in effectively curbing long-term urban GHG emissions (notably from transport), although this type of instrument has not been shown to be effective in the short term (Greene and Schafer, 2003; Rietveld, 2006). Cities’ reactions to changes in the spatial structure (involving the relocation of activities, new buildings and new infrastructure) occur with a certain time lag. Mismatch between land use and transportation policies has all too often aggravated traffic congestion around metropolitan cities. For instance, the introduction of a beltway around Seoul in 1999 was succeeded by the construction of five new cities (Bundang, Ilsan, Pyeongchon, Sanbon, and Jungdong) around Seoul three years later, leading to considerable traffic congestion. Another case is the development northwest of the Yong-in area.