This study has assessed the relationship between vehicle colour and crash risk through the analysis of real crash outcomes described in mass crash data reported to police in two Australian states. A stratified induced exposure study design was employed identifying vehicle to vehicle crashes and crashes involving unprotected road users as those having a risk dependent on vehicle colour whilst exposure was induced from single vehicle crash involvement. Analysis was stratified by vehicle type, light conditions and jurisdiction of crash. Results of the analysis identified a clear statistically significant relationship between vehicle colour and crash risk. Compared to white vehicles, a number of colours were associated with higher crash risk. These colours are generally those lower on the visibility index and include black, blue, grey, green, red and silver. No colour was statistically significantly safer than white although a number of other colours could not be distinguished from white statistically in terms of relative crash risk. The association between vehicle colour and crash risk was strongest during daylight hours where relative crash risks were higher for the colours listed compared to white by up to around 10%. Comparison of analysis results between the two states of Australia analysed suggested that vehicle colour also has an association with crash severity with lower visibility colours having higher risks of more severe crashes. Furthermore, the results also suggested that environmental factors can also modify the relationship between vehicle colour and crash risk although further work is required to quantify this. (Author/publisher)
Abstract