title: Influential factors in freeway crash response and clearance times by emergency management services in peak periods.
abstract: OBJECTIVE
  Various factors influence the time performance of emergency management personnel when a freeway traffic crash occurs. The proper identification and prioritization of factors that contribute to emergency management services' response times and clearance times result in better usage of taxpayer resources.
  
  
  METHODS
  Use of a proportional hazard-based Cox-regression model analyzed statewide, peak-period, traffic crash data from 1999 Ohio logs. These data included time performance measures of emergency management services.
  
  
  RESULTS
  Traffic crash severity had the most effect on response times. Those crashes involving injuries or fatalities had up to 20% less emergency management service response times than "property damage only" crashes. Environmental factors such as weather or roadway conditions had minimal effect on response times to traffic crashes. Day of week, urban or rural area, off or opposing-lane crash location, number of vehicles involved, heavy vehicle involvement, and response time significantly affected clearance time and the resulting total time during peak periods.
  
  
  CONCLUSIONS
  By assessing resources currently dedicated to insignificant factors, emergency management services can further improve response times to those casualties that crucially need emergency services. By accurately identifying and deciphering traffic crash severity from initial field reports, services can further improve. Moreover, improvements in crash severity prediction reduce "false alarms" for emergency services. The improvements reduce the probability of a very short response time for a property damage only crash in which initial reports implied a very severe injury. By focusing on factors that significantly reduce traffic crash clearance times on freeways in peak periods, more reductions in average delay experienced by freeway users, in fuel consumption, and in motor vehicle emissions can occur.
authors.affiliation: Urban Transportation Center, University of Illinois at Chicago, 412 South Peoria St., Suite 340, IL 60607, USA. leejportfolio@gmail.com
authors.forename: Jung-Taek
authors.initials: JT
authors.lastname: Lee
authors.forename: Joseph
authors.initials: J
authors.lastname: Fazio
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D019992:Databases as Topic; D004632:Emergency Medical Services / Q000706:statistics & numerical data*; D006801:Humans; D009820:Ohio; D016016:Proportional Hazards Models; D012424:Rural Population; D013997:Time Factors; D015599:Trauma Severity Indices; D014505:Urban Population