Response Time of Highway Traffic Accidents in Abu Dhabi Investigation with Hazard-Based Duration Models

Traffic incidents generate many adverse impacts, especially as far as traffic congestion, air pollution, fuel consumption, and secondary crashes are concerned. Therefore traffic incident responders and operators must know how to improve the efficiency of traffic incident management. This paper presents the results of an investigation into the effects of traffic accident characteristics on accident response time, with fully parametric hazard-based duration models with emphasis on the accelerated failure time metric. Accident characteristics and response times were obtained from Abu Dhabi, the capital of the United Arab Emirates. For an investigation into the factors affecting response time, data were retrieved from the Federal Traffic Statistics System and the Abu Dhabi Highway Collision Investigation Branch (AHCIB) for the period January to December 2009. For the purpose of this study, "response time" was defined as the length of time between the first report of the incident being received by AHCIB and the time that the first collision investigator arrived at the scene. After a goodness-of-fit test was conducted, a Weibull distribution with frailty was used. Results showed that various accident characteristics, including day of the week, month of the year, accident type, and location of the accident, affected response time. These results highlighted some weaknesses in the current highway accident management practices in Abu Dhabi, particularly the impact of lack of resources on the ability of the AHCIB to respond to an accident immediately upon notification of its occurrence. This paper suggests some measures designed to mitigate response problems.