GIS-Based Assessment of Public Transport Accessibility and Spatial Inequalities in Chennai

Abstract

The Global South is affected by increasing urbanization and vehicular density, creating significant challenges in urban mobility and public transport accessibility. Chennai, one of the major metropolitan cities of India, serves more than 3.2 million (32.24 lakh) passengers daily and is under increasing pressure to provide equitable and sustainable public transport services to its residents. This study proposes a framework to assess public transport accessibility and spatial inequality using a Geographic Information System (GIS). 
Public transport data were obtained from the General Transit Feed Specification (GTFS), road network data were obtained from OpenStreetMap (OSM), and demographic data were obtained from the Census of India. The study further assesses public transport accessibility through ward-level spatial analysis. The distance from bus stops to residential areas was determined using 400 m and 800 m walking-distance buffers. 
The findings suggest a significant improvement in accessibility, as indicated by ward-level bus stop coverage, which increased from 78.12% within a 400 m walking distance to 96.09% within an 800 m walking distance. However, some peripheral wards still show significantly lower accessibility, indicating spatial inequalities in public transport provision. The proposed GIS framework provides a low-cost, scalable decision-support tool for route rationalization, accessibility assessment, and evidence-based planning to support more sustainable and equitable urban mobility.