A GIS-Based Accessibility Modeling Process for Estimating Transit Travel Demand

Transit planning requires forecasting travel demand. In the aggregate transport modeling system, the forecasting is accomplished through a four-stage process, in which transit demand is separated from other modes during modal split. Transit travel demand may also be forecasted at a less aggregate level with other methods, such as regression and accessibility models. These disaggregate models measure transit demand based on walking distance to transit stops. This paper presents a pragmatic GIS-based accessibility modeling approach to transit demand forecasting. Principles and data requirements of accessibility models are described. Based on appropriate data model in GIS, an implementation framework is developed for applying the accessibility models.