Traditionally Road Authorities have taken a reactive approach to reducing road traffic crashes, focussing on the treatment of crash cluster sites. Although some crash cluster sites do still exist, these are becoming very infrequent and are often not robust; historical crash locations are not very good predictors of future crash locations. Although crash cluster sites are relatively infrequent, we still have high numbers of people being killed or seriously injured on our roads, so addressing such sites alone will not allow us to make the progress we need to make in terms of casualty reduction.

Road safety initiatives across the world and the UK are increasingly embracing Vision Zero and the Safe System. Vision Zero considers that it can never be ethically acceptable that people are killed or seriously injured within the road transport system, and directly challenges the prevailing view that death and serious injury are an acceptable by-product of mobility. The Safe System is the outworking of Vision Zero – it means the delivery of a road transport system that is designed so there is no possibility of death or serious injury. The iRAP (International Road Assessment Programme) approach provides a proactive route assessment methodology to identify and treat risk.