Identifying Spatial Gaps in Transit Accessibility to Maximize Market Potential

The focus of this paper is (1) to explore features available in commercial Geographic Information Systems (GIS) software and estimate accessibility index as a function of potential captive riders for each transit stop, and, (2) identify spatial gaps based on accessibility index to provide improved public transportation systems that maximizes market potential. Potential captive riders are identified within a pre-defined accessible walking distance or walking time (0.25 miles or 5 minutes) from each transit stop in the City of Charlotte, North Carolina. These riders comprise unemployed, household population with 0 or 1 automobiles, population by age group, low income population (< $25,000), and ethnicity. Results from statistical analysis conducted considering transit ridership and estimated accessibility index show that market potential can be maximized by selecting transit stop locations with high accessibility index or in locations with high accessibility index. Therefore, the methodology and estimated accessibility index to identify spatial gaps helps expand transit area coverage, identify new routes and transit stops.