Analysis of Factors Affecting Clearance Time of Freeway Incidents

Traffic incidents are the primary cause of delay in urban settings, reducing capacity and creating risks for both motorists and incident response personnel. As incident duration increases, the risk of secondary incidents or crashes also becomes a problem. In response to these issues, many communities have initiated incident management programs aimed at detecting, responding to, and clearing incidents in order to restore freeways to full capacity as quickly and safely as possible. This study involved the development of fully parametric hazard duration models to examine those factors impacting the time required by the Michigan Department of Transportation’s Freeway Courtesy Patrol to clear incidents that occurred on the freeway network in metropolitan Detroit. These models were developed using traffic flow data, roadway geometry information, and an extensive incident database. Four fully parametric hazard duration models are developed, each assuming a different underlying probability distribution for the hazard function. In general, each modeling framework provided similar results, though a log-logistic distribution is shown to provide a better fit for the incident clearance data in comparison to other distributions. Various factors were found to significantly affect incident clearance time, including the time of day and time of year at which the incident occurred, the geometric and traffic characteristics of the freeway segment, and the characteristics of the incident.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AHB20 Freeway Operations
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Ghosh, Indrajit
  • Savolainen, Peter Tarmo
• Conference:
  • Transportation Research Board 91st Annual Meeting
  • Location: Washington DC, United States
  • Date: 2012-1-22 to 2012-1-26
• Date: 2012

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 16p
• Monograph Title: TRB 91st Annual Meeting Compendium of Papers DVD

Subject/Index Terms

• TRT Terms: Incident management; Mathematical models; Time; Traffic incidents
• Subject Areas: Highways; Operations and Traffic Management; I73: Traffic Control;

Filing Info

• Accession Number: 01368401
• Record Type: Publication
• Report/Paper Numbers: 12-0458
• Files: TRIS, TRB
• Created Date: Apr 25 2012 8:00AM