A TOD planning model to review the regulation of allowable development densities around subway stations

Transit-oriented development (TOD) planning generally emphasizes development efficiency, but ignores the other two aspects of sustainability: environment quality and social equity. This study has developed a multi-objective programming model for TOD planning. Based on the concept of sustainability, three objectives are considered: maximizing subway system ridership; maximizing living-environment quality; and optimizing the social equity of land development. The decision variables are the ratios of floor space to site space (RFS) for different land uses in subway station areas. Meanwhile, the constraints include restrictions on land use density, land use combinations, and level of service facilities. The Chunghsiao-Fuhsing station area in Taipei is chosen as a case study to illustrate the model application and planning results. From sensitivity analysis, it is found that enlarging the upper bound of RFS can increase subway ridership, but at a cost of reducing social equity and living environment. It is not necessary to set the upper bound of the RFS greater than 70%, because subway ridership does not significantly increase, in this case study.