The Impact of Abandoned and Disabled Vehicles to Freeway Incident Durations

摘要

In most cases, abandoned and disabled vehicles are left within the roadway right of ways. It iscommon to find a vehicle left on the shoulder, median, gore area or on the travel lane for certainperiod of time. Experience from the state of Tennessee has shown that 78% of the freeway trafficrelated incidents are due to disabled and abandoned vehicles. It is hypothesized that the longerthe vehicle is left unattended within the right of way, the higher the probability of new incidentsand secondary crashes. This paper utilized 2004 to 2010 freeway incident data in Tennessee toevaluate the impact of the length of incident durations caused by disabled and abandonedvehicles. Analysis evaluated the impact of these incidents with respect to roadway location,queue lengths, weather conditions, towing times, lane closure, and the source of incidentnotification. Temporal factors, including the spectra of the time of the day, the day of the week,and the seasons of the year were evaluated with respect to the number of incidents and incidentdurations. Many disabled and abandoned vehicles were located in the left and right shoulderscompared to other roadway location. Parametric hazard based log-logistic survival model wasapplied to determine the factors affecting the abandoned and disabled vehicles incident duration.Number of closed lanes, length of the queue formed, construction zones, trucks and towinginvolvement were found to be significantly associated with longer incident duration.