Variable Speed Limit Control to Increase Discharge Rates of Freeway Incident Bottlenecks

Variable speed limit (VSL) schemes are developed based on the kinematic wave theory to increase discharge rates at freeway incident bottlenecks (BNs) while smoothing speed transition. The main control principle is to restrict upstream demand (in free flow) progressively to achieve three important objectives: 1) to provide gradual speed transition at the tail of an incident-induced queue, 2) to clear the queue around the BN, and 3) to discharge traffic at the stable maximum flow that can be sustained at the incident BN without breakdown. These control objectives are accomplished without imposing overly restrictive speed limits. This paper further provides remedies for the case of a reemerging queue at the BN as a result of an overestimated stable maximum flow. The results from a parameter analysis suggest that significant delay savings can be realized with the VSL control strategies.


  • English

Media Info

  • Media Type: Web
  • Features: Figures; References;
  • Pagination: pp 117-132
  • Monograph Title: Celebrating 50 Years of Traffic Flow Theory: A Symposium. August 11-13, 2014, Portland, Oregon
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 01604716
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: Jun 30 2016 1:48PM