Transit accessibility: A new definition of transit connectors

Document Type

Journal Article

Publication Date


Subject Area

place - europe, place - urban, planning - methods, planning - service improvement


Transit accessibility, Centroid connectors, Walking, Transit modeling


Transit accessibility is a key determinant in explaining transit use and promoting transit policies. The improvement of transit access conditions is deemed to improve the overall quality of the transit service, the user experience, and ultimately, the transit ridership. In transport modeling, however, transit accessibility is still modeled in a very crude manner based on centroid connectors. This approach does not render actual walking conditions as encountered by transit users. The current paper proposes a new definition of transit access for transport modeling purposes. In contrast to current practice which is based on centroid connectors, this new definition uses high resolution spatial data to model actual access and egress conditions to and from transit facilities. The new approach relies on the spatial distribution of potential transit users and their probability of using transit facilities. Two automatic methods have been developed: selection of accessible transit facilities on the basis of their proximity and computation of the length of connectors using distance decay functions.

Results from the urban area of Lyon, France, show the significant contribution of the new definition. In comparison to the standard method, the new definition is found to improve main transit modeling outcomes and to better reproduce observed data. This new method can assist transport planners and public authorities to evaluate transit policies more accurately and instruct more appropriately policy makers.


Permission to publish the abstract has been given by Elsevier, copyright remains with them.


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