This paper describes the results of a project funded by FHWA to develop a web-based accessibility toolkit for transportation planners. The free toolkit will provide simple, but powerful analytical tools to enable evaluation of accessibility changes associated with transportation improvements. In the paper, we will describe accessibility measures and how the toolkit can be used to inform planners and the public on the likely impacts of projects and plans.

Accessibility refers to the possibilities of traveling to destination opportunities and the level of service associated with a wide range of travel options. Accessibility can be assessed for both person travel and freight movements and for all modes, not just vehicular modes. Increasing travel options or improving their quality and performance spatially and/or temporally increases accessibility.

The focus of the toolkit is to provide methods, software, and data enabling calculation of the accessibility associated with transit, pedestrian, bicycle, and car travel. In the paper, we describe the analytical and technical challenges to achieving this goal for each of these modes. For transit, we have implemented a means of calculating accessibility using the GTFS data feeds that are increasingly available. For other modes, we have developed a means of incorporating planning model data and other GIS data in the accessibility calculations. We also describe cartographic and other visualization techniques that are utilized in this web application. Lastly, the use of calculator is illustrated with examples from several MPO regions.