Accessibility Indicators for Transportation Planning Using GIS

In this paper a method to create GIS-based accessibility indicators is presented. The method allows to create person-by-person and store-by-store (disaggregate) accessibility indicators but also to derive zonal summary (aggregate) indicators that can be used in more traditional transportation planning applications. These indicators have also been used as explanatory variables in person-based transportation planning models illustrating the relationship between accessibility and shopping behavior, which in turn can be used in the trip generation models in the usual travel demand forecasting process. In this study the use of network shortest path, Gaussian function, parameter value 4.856, and employment intensity as attraction measures created an accessibility with the best behavioral foundation. The study also shows that building GIS-based accessibility indicators is feasible and provides better information than aggregate accessibility indicators.