We support Local Authorities to take a proactive risk reduction approach through iRAP surveys . These can be done at the network level (e.g. surveying the whole of the Major Road Network or A Road Network) or individual routes that have been identified (sometimes through our Crash Risk Mapping work) for investment.
Why do an iRAP Survey?
The iRAP methodology helps us to take a proactive risk management approach to tackling road infrastructure safety – a similar proactive approach as is taken in safety critical fields like oil & gas, mining and rail. Rather than waiting for collisions to accumulate before we take action we can use the iRAP methodology to take action based on known risks.
Historical collisions are now less predictive of future crashes than ever before. Over the last 30 years the number of deaths and serious injuries has fallen considerably which means that collisions are sparsely distributed across the road network. The overall numbers are still too high, however the sparse distribution means that robust collision cluster sites (hotspots or blackspots) are relatively rare. Where collisions appear to cluster, the low numbers mean that there is a lot of noise in the data and the numbers will go up and down naturally. What this can mean is a phenomenon called Regression-To-the-Mean (RTM).
iRAP helps us to fill in the gaps in our knowledge of risk along whole routes and networks. Every 100m over 50 characteristics of the route are recorded, and a scoring system (based on known relationships between the road characteristics and crash likelihood or severity) provides a Star Rating Score value for each road user group in the model (vehicle occupants, motorcyclists, pedestrians and cyclists) and for each relevant road collision type for each of these user groups. What that means is a detailed understanding of the risks present on the route or network.
Each route or network is calibrated using route or network level information about historical collisions, so effectively the model is being told the rough shape of the casualty issue on the route or network. Then the Fatal and Serious Injuries expected at each 100m location is estimated based on the calibration, the Star Rating Score (reflecting individual risk) and the user flows (exposure).
The model uses the Fatal and Serious Injury estimates to develop a model generated investment plan that can provide inspiration to road safety engineers. In reality though, those road safety engineers will need to take those suggestions, and apply their knowledge of local practice, standards and acceptability to develop User Defined Investment Plans.
To do this we use the Route Review process and tool. This supports practitioners in Safe System treatment development and allows users to create business cases for investment.
The process and toolkit mean we can systematically treat risk and, one day, eliminate it.
Safe System Fatal Review Panels
The Safe System requires road safety practitioners to move away from only determining the causation of collisions and establishing culpability following a collision, to also identifying systemic failures which, if corrected, could prevent the severity of similar future high severity collisions.
Inspired by the Cambridgeshire and Peterborough Vision Zero Partnership Collision Review Panel which was established in 2023 to help identify system failures and mitigations, RSF initiated a project to replicate this work in other locales. In 2024/2025 RSF identified best practice and a terms of reference for Safe System fatal review panels, developed training materials for personnel, and delivered training to three new fatal review panels in England.
