Transit network expansion and accessibility implications A case study of Gwangju metropolitan area, South Korea

Abstract

Densely populated metropolitan areas require a well-functioning transit system to serve the travel demands in the area. Because of this, transit networks have evolved with the growth of the metropolis and this has entailed changes in the network’s accessibility. This study aimed to explore the changes in accessibility following major transit network expansions in the Gwangju Metropolitan Area. The time distance based accessibility was calculated at three different transit provision stages. The global accessibility measure indicated that the construction of subway line 1 would improve the transit accessibility significantly, but the second line would not have as much impact as line 1. The spatial distribution of accessibility changes appeared to deliver a similar message. However, our findings contradicted with the criticism of the current subway line 1, whose modal share has stayed quite low since its operation, and the expectation of the planned subway line 2. This might be due to the limitations of our definition of accessibility, but it also could be understood that the under-use of subway line 1 hindered the realisation of accessibility impacts in reality.