What are iRAP star ratings?

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iRAP (the International Road Assessment Programme) is the umbrella programme for Road Assessment Programmes (RAPs) worldwide that are working to save lives. Click here to find out more about iRAP.

Regional RAPs, such as EuroRAP the European Road Assessment Programme, drive advocacy and the application of RAP tools and initiatives to best suit the local context and maximise the number of lives and serious injuries saved. The Road Safety Foundation is the UK Member responsible for managing the programme in the UK. To find out more about EuroRAP click here.

iRAP and its partners have developed a suite of road safety tools – Risk Mapping, Star Rating, Safer Roads Investment Plans and Policy and Performance Tracking that help partners across the world inform sound investment by governments that saves lives and unlocks the benefits to families, communities, business and health systems through reduced road trauma.

Star Ratings are based on road inspection data and provide a simple and objective measure of the level of safety which is ‘built-in’ to the road for vehicle occupants, motorcyclists, bicyclists and pedestrians. More information on Star Ratings can be found here.

Star Ratings are produced by identifying and recording the road attributes which influence the most common and severe types of crashes, based on scientific evidence-based research. In this way, the level of risk to an individual road user on a particular road section or network can be defined without the need for detailed crash data.

Broadly speaking, every extra star rating results in a halving of crash cost in terms of the number of people who are killed and seriously injured.

Five-star roads are the safest while one-star roads are the least safe.

Where Star Ratings represent the individual risk of a road to a user (i.e. likelihood and severity of a crash), fatality estimations represent collective risk which accounts for exposure (i.e. road user volumes) and actual crash rates.

Estimation of fatalities and serious injuries (FSI) can be used in Investment Plans to assess the benefits and costs of implementing infrastructure safety countermeasures on a road. FSI estimates are made for each 100m segment of the existing road under existing conditions.

Investment Plans draw on data underpinning Star Ratings and FSI Estimates to determine the most cost-effective road upgrades and prevent deaths and serious injuries. More than 90 road improvement options can be analysed by the iRAP model to provide an optimised investment of likely safety countermeasures and the business case for that investment.

Investment Plans can support investment decision making on existing roads and within road designs.  Planners, designers and engineers can use this information together with their expertise and local knowledge to develop detailed implementation plans and designs and measure the ultimate impact on Star Ratings and FSIs saved.

The iRAP Star Rating Demonstrator is a tool within ViDA that enables Star Ratings and Star Rating for Designs (SR4D) at individual locations. With the Demonstrator, it is possible to quickly produce a Star Rating and test the effect that changes to road attributes will have in risk and Star Ratings.

ViDA is iRAP’s free-to-air online platform. It is the data processing engine for Star Ratings, FSI Estimates and Investment Plans, hosting data and analysing results, and the portal for iRAP’s tools: SR4D, the Star Rating Demonstrator. Access to ViDA is available here.


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