Risk Mapping

In countries where detailed crash and traffic data are available, EuroRAP risk maps give an objective view of where people are being killed or seriously injured on a road network and where their crash risk is greatest. They capture the combined risk arising from the interaction of road users, vehicles and the road environment.

The emphasis of Risk Mapping is on identifying high-risk routes rather than “blackspots” or “cluster sites”. The cost of proactively treating known areas of high risk by upgrading the safety detailing along a length of road is often far lower than piecemeal change once a crash has occurred.

Road sections are allocated into colour-coded categories from high risk to low :

colour_bandings_200x121

Because the large majority of fatal and serious crashes occur outside major towns and cities, EuroRAP Risk Mapping concentrates on rural roads. Typically national programmes map higher tier road networks first, where data are most often available, developing to regional networks over time. The aim is to include the network where large numbers of people are being killed and seriously injured.

What Risk Maps Do & Don’t Show

Risk maps based on crash rates do not show the extent to which the behaviour of a specific road-user might result in the risk being higher or lower than the average. They also do not show the extent to which the road-user can make a mistake, and recover from it without serious injury.

What they do illustrate is the risk of an individual road-user, or to the community as a whole, being involved in a road accident, providing that they are behaving within acceptable boundaries of road use – for example, not intoxicated, not using a mobile phone, and obeying speed limits.

Maps make it easy to identify the safest and most dangerous road sections within a region or country and, by comparing maps for different countries, enable European comparisons of safety performance. An important aspect of EuroRAP’s work is to develop partnerships between road-user organisations and road providers, and to produce results that will be meaningful to the motoring public, policy-makers, highway providers and operators alike.

EuroRAP maps give various insights into risk and can be used to support the differing needs and levels of expertise of road safety stakeholders. Under EuroRAP’s Risk Mapping protocol, safety indicators based on the road network, crash numbers and traffic flow can be used to produce mapping showing:

  • Crashes per kilometre used by road authorities to reflect more broadly how the total risk to all road-users is distributed across a network;
  • Crashes per vehicle kilometre travelled showing the risk to individual road users as they move around a network;
  • Risk in relation to roads with similar flow levels;
  • Economic potential for crash reduction showing the opportunity for investment from Safer Road Investment Plans.
Due to differences in the definition and reporting of fatal and serious accidents across Europe the raw data collated for each country is adjusted to allow comparisons of relative safety risk.

To bring the data in line to a European norm, different thresholds for each risk rate banding (low, low-medium, medium, medium-high, high) are used. This adjustment is based on the ratio of the number of fatal accidents to the number of serious accidents

The aim of this adjustment is not to change one country’s accident reporting practice to fit that of another, nor is it to artificially increase or reduce rates in any country. The adjustment simply gives a better estimate of relative long term accident rate for each link within a national network.

Where material included on the site has not been subject to this adjustment, and therefore, where it cannot be compared directly with other countries, this is clearly marked.

A typical EuroRAP road section is 20 kilometres long with 20 fatal and serious crashes in just 3 years – as much as a major rail crash.

Some short sections of road (e.g. link roads), and some that carry low traffic volumes are removed from the sample. These short sections (e.g. less than 5km), those that have small accident totals (e.g. less than 7), or carry low traffic volumes (e.g. less than 3,000 per day) are more likely than others to experience greater year-to-year variation in accident rate and are therefore more likely to change risk rating from one period to another.

For more detailed information on the criteria and methodology used, refer to the following Technical Reports:

December 2004: EuroRAP Year 1 (2003) update – performance tracking of roads

May 2004: Year 1 Technical Report

May 2003: Pilot Phase Technical Report

May 2003: Summary of Pilot Phase Technical Report

The first Risk Bands were defined for Europe in the Decade to 2010 using data from Britain, Sweden and the Netherlands. During this period, road deaths have broadly reduced by 50% across the countries undertaking Risk Mapping. The European Commission and national governments have now set new targets for a further 50% reduction for the Decade to 2020. The result is that the ‘low risk’ band is now an exceptionally ‘soft’ target. Risks in all other bands are now substantially understated.

The next set of Risk Bands have therefore been defined in the Decade to 2020 by halving the thresholds for Risk Bands 2010.

Screen Shot 2014-12-18 at 15.11.02

Screen Shot 2014-12-18 at 15.11.09