Travel Time Based Performance Measures to Assess the Effect of Crashes by Severity

Nonrecurring events such as crashes contribute to significant levels of congestion on roads. Travel time-based performance measures help not only quantify the effect of crashes by severity but also help use the outcomes to better plan and manage the transportation system. These performance measures can be broadly categorized into travel time (minimum or free flow, average, and maximum), travel time percentiles (10th, 15th, 50th, 85th, 90th, and 95th), and travel time reliability indices. However, not all travel time-based performance measures are applicable and suitable to assess the effect of crashes by severity. Questions, such as which performance measure should one use to assess the effect of crashes by severity on transportation system performance, and, can travel time-based performance measures be used to quantify non-recurring congestion and identify solutions from mobility and safety perspective, have been lingering in the minds of researchers and practitioners. Moreover, the relationship between crashes by severity and travel time-based performance measures varies by the time-of-the-day and day-of-the-week. This paper, therefore, focuses on examining the relationship between crashes by severity and travel time, travel time percentiles as well as travel time reliability indices, by time-of-the-day and day-of-the-week, to recommend suitable performance measures to assess their effect. The number of fatal and injury type “A” crashes is most of the times weakly correlated with travel time-based measures, with the exception of maximum travel time. The injury type “B” plus injury type “C” crashes are strongly correlated with travel time reliability indices only on Sunday from 4 PM to 5 PM. The trends in correlation with travel time-based measures are similar for property damage only (PDO) crashes and the number of total crashes, possibly indicating that frequency effects travel time-based measures more than severity of crash.


  • English

Media Info

  • Media Type: Web
  • Features: References;
  • Pagination: pp 221-231
  • Monograph Title: International Conference on Transportation and Development 2018: Connected and Autonomous Vehicles and Transportation Safety

Subject/Index Terms

Filing Info

  • Accession Number: 01867075
  • Record Type: Publication
  • ISBN: 9780784481530
  • Files: TRIS, ASCE
  • Created Date: Dec 13 2022 10:05AM