Following the World Health Organisation, nearly half of those dying on the world's roads are vulnerable road users (VRU). This proportion is much greater in low- and middle-income countries, because of the greater variety and intensity of traffic mix and the lack of separation from other road users, than in high-income countries. Compared to other road users the vulnerable user group is particularly exposed to injury as they are not protected by a vehicle shell.

For years, pedestrians, cyclists, moped riders, etc. have been considered in the PIARC guidelines on road safety. However, considering that worldwide the total number of vulnerable road users deaths and injuries remains unacceptably high the PIARC 2012-2015 technical committee "Design and Operation of Safer Road Infrastructure" decided to review and update its guidelines, checklists and manuals emphasizing on the safety of this group of users.

As a first step a PIARC common agreed definition of VRUs has been proposed. This definition focuses on road users who are at great risk because of insufficient physical protection or because of relative high speed difference with potential conflicting modes. Through this definition a specific attention is given to four main categories of road users; i.e. pedestrians, cyclists, riders of powered two-wheelers, light duty farm vehicles or animal drawn vehicles. In a second stage the working group worked on listing infrastructure safety treatment solutions to mitigate risks for VRU sub-groups along urban and interurban roads.

In parallel the road safety audit (RSA) and inspection (RSI) checklists have been amended to account for the newly adopted definition. Checklists have been made more consistent to address safety issues related to pedestrians, cyclists, powered two-wheelers and other VRU subgroups.