The Effects of Seoul’s Greenbelt on Travel Mode Share in Its Inside and Outside: A Spatial Panel Econometric Analysis

Abstract

The primary purpose of urban growth management policies is to control urban sprawl and induce the diversification of travel mode share. Hence, how the greenbelt, as an urban containment policy, affects travel mode share is one of the important issues in understanding the efficacy of urban growth management. To analyze it for the Seoul Metropolitan Area (SMA), which has designated its greenbelt for more than forty-five years, this study implemented the spatial Durbin panel regression for the years from 2002 through 2016. Results showed that the greenbelt increased the use of public transportation and decreased car use, but it tended not to increase the use of nonmotorized modes of transportation such as bicycling and walking. There also turned out to be U-shaped (convex) relationships both between population density and car use and between the former and bicycling. Meanwhile, an inverted U-shaped relationship was observed between population density and public transportation mode, which was statistically significant. Based on these results, it can be said that a public transportation system outside of the greenbelt is needed for increasing its accessibility. To promote the use of public and nonmotorized transportation, it will also be important to determine the appropriate urban density.