Evaluating the Effect of Street Network Connectivity on First/Last Mile Transit Performance (SWUTC/11/161106-1)

This study defines a novel connectivity indicator (CI) to predict transit performance by identifying the role that street network connectivity plays in influencing the service quality of demand responsive feeder transit services. This new CI definition is dependent upon the expected shortest path between any two nodes in the network, includes spatial features and transit demand distribution information, and is easy to calculate for any given service area. Simulation analyses over a range of networks are conducted to validate the new definition. Results show a desirable monotonic relationship between transit performance and the proposed CI, whose values are directly proportional and therefore good predictors of the transit performance, outperforming other available indicators typically used by planners. This study also presents a methodology to identify and locate critical links in a grid street network system of any size for feeder transit services. A critical link can be defined as that link that when eliminated from or appended to an existing network would cause the largest change in the network connectivity and consequently transit performance. Easily computable formulas are provided and validated by simulation analyses. Useful insights indicate a monotonic decrease in link criticality as we depart from the centrally located links to those located at boundaries.