ACCESSIBILITY MODELLING USING GIS

The Accessibility Modelling System described is based on ARC/INFO and uses a combination of network and land use/demographic information to represent the accessibility measures. Transport networks can be readily developed to represent walk, cycle, bus, rail, LRT and car modes which can be constructed manually from digital data available from Ordnance Survey. The land use information can be provided by the readily available 1991 OPCS data, which includes information on population, employment, car ownership, travel to work mode etc, at a zone level as fine as enumeration districts. The GIS based system can be used from single point accessibility, for instance, to find the optimum location for a bus-stop or LRT station that maximises catchment areas, or as an aggregate measure to map accessibility levels and determine where accessibility improvements should be made. This paper expands upon the use of GIS in accessibility modelling for transport planning and gives examples of how the system has been used to provide solutions in real projects. For the covering abstract see IRRD 881556.