Sometimes It Pays to Be Lazy When Responding to Freeway Incidents

Traffic Operations Centers (TOC) deal with incidents. These incidents vary by location, time of day, and degree of disruption. Operator responses vary by how quickly they are implemented and the degree of operational actions they take. Operators can react instantaneously, or they can wait to assess the incident’s impact. They can divert traffic from an entire highway or simply implement a mild variable message. The paper presents an analysis of critical incident locations on a test Salt Lake Valley freeway network. The microsimulation modeling is through VISSIM. We define Closure Level as the percentage of lanes closed due the incident. The Incident Duration is the interval from lane closure to traffic taking back the obstructed lane or lanes. The Response Time is the interval between the onset of the modeled traffic impact and the implementation of the Variable Message Sign Levels (VMS Levels). The VMS Levels are four levels of driver response to the intensity of the message. While no messages are offered, we identify a range of proportion of drivers who comply with diversion recommendations. This paper analyses a wide range of incidents and responses. As expected, the resulting degree of incident disruption is mitigated by the speed of response and the proportion of drivers who divert. However, for certain minor incidents, a “laid back” approach is the better option. This counter intuitive finding can be characterized as “too much diversion, too soon, for too many drivers”.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee AHB10 Regional Transportation Systems Management and Operations
  • Corporate Authors:

    Transportation Research Board

    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Authors:
    • Tasic, Ivana Milorad
    • Martin, Peter T
    • Zlatkovic, Milan
    • Chaudhuri, Piyali
  • Conference:
  • Date: 2012


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 17p
  • Monograph Title: TRB 91st Annual Meeting Compendium of Papers DVD

Subject/Index Terms

Filing Info

  • Accession Number: 01370363
  • Record Type: Publication
  • Report/Paper Numbers: 12-4194
  • Files: TRIS, TRB
  • Created Date: May 16 2012 4:09PM