System-Optimal Re-routing Transit Assignment Heuristic: A Theoretical Framework and Large-Scale Case Study

Traditionally, transit network assignment is modelled based on the user equilibrium principle where individual passengers are assumed to take paths that would minimize their travel time. Models that follow this principle result in sub-optimal system performance when the assigned lines become overcrowded. This study presents a new framework for the transit assignment problem to address the system performance of an overcrowded transit network while integrating individual travel needs. It proposes a novel approach, called System Optimal Re-Routing Transit Assignment Heuristic (SORTAH), which produces a user-constrained system optimal solution by targeting the reduction of the number of overcrowded segments and spreading out the demand to better utilize routes that are under capacity. SORTAH minimizes the overall congestion effects of a transit network and leads to a better performing solution than that of a user equilibrium model, while simultaneously guaranteeing superior fairness compared to the pure system optimal model. A large-scale real-world application was conducted on the Toronto Transit Commission (TTC) network. SORTAH reduced the number of overcrowded routes on the TTC network while total travel time stayed virtually the same. Critical systemic gaps that need to be addressed in order to reduce the overall network congestion were uncovered. It also revealed that realistic passenger paths are bounded by existing network design and capacity.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee AP010 Standing Committee on Transit Management and Performance. Alternative title: System-Optimal Re-routing Transit Assignment Heuristic: Theoretical Framework and Large-Scale Case Study.
  • Corporate Authors:

    Transportation Research Board

    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Authors:
    • Cheung, Landy L
    • Shalaby, Amer S
  • Conference:
  • Date: 2016

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 18p
  • Monograph Title: TRB 95th Annual Meeting Compendium of Papers

Subject/Index Terms

Filing Info

  • Accession Number: 01589068
  • Record Type: Publication
  • Report/Paper Numbers: 16-2333
  • Files: PRP, TRIS, TRB, ATRI
  • Created Date: Feb 1 2016 9:26AM