Measuring Service Gaps

The integration of transit needs into transit accessibility indexing is important for evaluating existing transportation systems and service gaps and for identifying priority areas for investments in transportation infrastructure. This study detailed an indexing model for accessibility of transit need and focused on the necessity of evaluating transit needs and transit accessibility simultaneously. A need index was developed to identify areas in high need of public transit services from economic and sociodemographic information, and a composite accessibility index was developed to identify levels of access to transit services and shortcomings in providing service. The need for transit service was then modeled as the lack of transit accessibility, and the model correlated different access indicators with their ability to predict transit service need. This model mapped areas with different levels of transit accessibility and transit needs by using a single score, which may be easily interpreted by planners who examine transit equity. The model was applied to the city of Meriden, Connecticut, and results were compared with a general approach for consistency and effectiveness. The usefulness of the model was also highlighted through a representative example of the model's application.