Re-investigation of roadside risk factors associated with run-off-road casualty crashes in Victoria, Australia

This paper examines the road side design features related with run-off-road collisions on rural undivided roads in Victoria, Australia. Run-off-road casualty crashes comprise around fifty percent of all single vehicle crashes that take place in rural roads with a speed limit 80km/h or above in Victoria. Five-year crash and road design inventory data from Victoria were analysed. A poisson regression modelling approach was adopted to estimate run-off-road crash frequency. Modelling results indicated that narrower hazard offset (clear zone) increased the likelihood of run-off-road casualty crashes. Tight road curvature was a strong and consistent predictor of run-off-road casualty crashes. Findings from the study can lead to more effective safety countermeasures that can substantially reduce the injuries and fatalities associated with run-off-road collisions.