Drivers' injury severity in single heavy vehicle crashes on Melbourne metropolitan highways and freeways

Australia is extensively using large heavy vehicles to transport goods and material. In Melbourne, road freight has grown by about 5 per cent per annum between 1971 and 2003 and it is estimated to grow from 10.3 billion tonne-kilometres in 2003 to 16.9 billion tonne-kilometres in 2020. With the increase in road freight, there will be an increase in the heavy vehicle traffic proportion, and consequently, an increase in the possibility of collisions involving heavy vehicles. Furthermore, the larger size and weight of heavy vehicles will also contribute to increasing the crash and injury severity. In Australia, heavy vehicles account for only 3% of the total number of registered vehicles, but are involved in 18% of the total road fatalities. In the past three years, the number of fatal injuries involving heavy rigid trucks has increased by 8.5% per annum. The objective of this research is to determine the factors influencing drivers' injury severity in single vehicle collisions involving heavy vehicles on highways and freeways of Melbourne Metropolitan area using a binary logit model. Our results show that drivers of prime mover B-double and B-triple type heavy vehicles are more likely to be severely injured in run-off road crashes. Additionally, heavy vehicle drivers wearing safety restrain are less likely to suffer severe injuries in single vehicle crashes on urban highways and freeways.