Transit Accessibility Deficit and Commute Mode Share: Better Driving Accessibility, More Transit Riders

Access to jobs is a powerful metric for evaluating transportation opportunities, integrating time and distance across the available network. The common currency of the number of jobs reachable in a given time frame from a given location also allows comparison across different modes, such as driving and public transport, recognizing that in most cases access to jobs by driving is greater than by transit. This paper defines transit accessibility deficit as the cumulative number of jobs reachable by driving, less the cumulative number of jobs accessible by taking transit for the same travel duration, and explores how this metric explains differences in the aggregate transit commute mode share in the Minneapolis–Saint Paul, Minnesota metropolitan region. The authors use a hierarchical probabilistic model to predict transit mode share based on accessibility deficit data and a synthesis variable, transit market area, which captures population density, employment density, vehicle ownership rates, and intersection density. Contrary to expectations, transit mode share is strongly positively related to transit accessibility deficit, such that the highest transit mode share occurs in the block groups with the largest access deficit relative to driving. This positive association reflects the particulars of the concentric distribution of jobs in the Twin Cities, but suggests commuter mode choice is independent of the overall comparative accessibility offered by driving and public transit.


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 16p

Subject/Index Terms

Filing Info

  • Accession Number: 01763726
  • Record Type: Publication
  • Report/Paper Numbers: TRBAM-21-03226
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 23 2020 11:10AM