The relationship between the traffic flow from commercial vehicles and road safety: a case study of the M8 motorway

Abstract

Road accidents are one of the greatest externalities of the contemporary transport networks. In the meantime, freight transportation is rising swiftly in all around the world, as the ever-growing trends in e-commerce generate the need for businesses of more immediate goods’ distribution and shorter delivery cycles. In addition, both the number of fatalities and the road freight lifted by trucks in the roads of Scotland have seen a rise during the past years. This thesis intends to shed light to the relationship between the traffic flow from commercial trucks and accidents on motorways. This has been achieved by examining the association between the AADF from commercial vehicles with both accident frequency and accident severity, using two appropriate statistical models, namely Negative Binomial and Binomial logistic models respectively. Empirical data were collected from the M8 motorway for the years 2014-2017. The findings of this thesis reveal that the AADF from commercial vehicles has little or no statistically significant relationship with the accidents’ occurrence, in terms of both accident frequency and severity. An accident which occurs between 12:00am-5:59am is found to be more likely fatal/severe than when occurring at any other time, a fact that could possibly be linked to the preference of freight operators and retailers towards choosing more night-time freight trips and off-hours deliveries. Limitations on delivery times and establishment of resting areas on roadways can contribute in enhancing road safety.