The development and application of transit accessibility measures by geographic information system technology are described. The approach allows transit planners to focus on access to transit routes and bus stops at the neighborhood level and draws attention to the significance of the walk access mode to transit. Then land use, population, and employment characteristics are incorporated into the evaluation of transit service. A case study example of a "what-if" scenario for evaluation of transit service alternatives is discussed. Conclusions are offered about the use and further development of the approach for transit planners.

Literature demonstrating how to use geographic information systems (GIS) effectively for transit origin-destination (O-D) data analysis is rather inadequate to date. Other than geocoding O-D survey data to point locations, not much attention has been accorded GIS as either a tool for checking survey data quality or for validation of data analysis. The purpose here is to demonstrate how the Orange County Transportation Authority applied GIS technology effectively to project transit passengers’ mobility patterns with greater accuracy and consequently strengthen the validation database for travel demand forecasting analysis with respect to transit planning. In addition to the use of traditional statistical methods for weighting procedures, this study relied on analytical GIS functions to achieve the following two objectives: ( a) incorporation of the spatial element while expanding the weighting factors, and ( b) validation of the weighted O-D survey returns with passenger counting data derived from other independent data sources. This project demonstrates both the usefulness of GIS technology in its ability to improve the quality of travel survey data and its value in combination with weighting-factors expansion methodology. In addition to the traditional statistical weighting methodology, a spatial component was incorporated as a criterion for enhancing the expansion results of the O-D data. Furthermore, comparative analysis with transit passenger counts and transfer data volumes were used to validate the findings of the weighting methodology. The results support the conclusion that GIS can greatly improve O-D data quality and statistical representation.

This paper describes how a bus stop measuring system can be developed not only to achieve transit operation efficiency but also to collaborate proactively with urban planners and traffic engineers on transit–land use interface activities. The measuring system was developed by identifying transit performance variants at the bus stop level with the use of a dynamic composite weighting factor approach on a geographic information system platform. A tier structure framework was used to categorize the composite scores of bus stops into six groups. Specific transit improvement actions were then tailored on the basis of their bus stop characteristics. Two project application examples are presented in this paper. One is a bus stop thinning project for speed improvement, and the other is for prioritizing capital project improvements. As various active transportation programs emerge to encourage local jurisdictions to plan transit connectivity with other community gathering places, this bus stop measuring approach presents a con tinued process to monitor their performance. It is also used to strengthen integration with other street improvement activities, including pedestrian paths and bikeways, to create a safe and sustainable urban environment.