This study measures and estimates the potential environmental and economic impacts of introducing transit-oriented corridors in Korea. By developing a TOC planning model concept through regression analysis, authors examine the relationship between TOC planning factors and transport modal share, and the impact of transit accessibility on transport modal choice. Several conclusions were drawn from the results; first, in order to promote mass transit, the area′s residential and commercial features must be intensified through a combination of mixed-use and a low ratio of road. Second, the transit modal choice analysis revealed that accessibility to mass transit is an important variable in determining its usage, along with the number of blocks per unit area and the pedestrian environment of the vicinity. Third, the results suggest that strengthening city-wide reliance on mass transit is effective in reducing environmental hazards to a significant degree: with a ridership ratio increase expected in the range of 3.5 to 5.9%, the resulting decreased road traffic would reduce CO₂ emissions by 391 to 686 thousand tons. Finally, in terms of boosting the regional economy, higher pedestrian volumes of commuters would increase annual income for neighborhood retailers in the range of 7.4 to 13.6 million dollars.