Based on a series of stakeholder consultation events the main content, outputs and functionality were developed and used as the basis of the DSS development. This enabled a coding protocol to be developed that would be used to record data from many studies of infrastructure, vehicles, road user behaviour or post-crash care. Studies were selected for the DSS prioritised according to criteria based on specific search terms, peer reviewed sources, recency and EU validity. In some cases, meta-analyses of specific risks or measures were available, where possible these were updated with the results taking preference over individual studies.
A total of 1301 individual studies of crash risk factors or the effectiveness of road safety interventions were selected and together these enabled over 7,500 estimates of risks or measures. These estimates were extracted from the studies and entered onto a back-office database together with a large amount of supporting data to enable future interpretation and comparisons.
To enable users of the DSS to identify suitable measures for the risk factors of concern a new taxonomy of risks and measures was developed. This was used as the primary link between risks and measures and provided the core of the functionality of the DSS and it ensured that all relevant measures, whether infrastructure, road user, vehicle or post-crash care based, would be identified.
A new web interface to the DSS was developed to provide access to the studies with a set of training videos and reference information to enable intuitive use. Stakeholder consultations were used to identify the preferred set of entry points that most users would use.
A standard set of results are generated by the DSS to ensure the appropriate level of detail was available for all users. Summary information provides a short overview of the nature and magnitude of the risk or the effectiveness of a measure, indicated through colour coding. A list of relevant studies is generated with links to the original information. The results page also gives access to a longer document that gives a complete description of the underpinning evidence and an interpretation of the research for policy-makers. Full information about the relevant studies is made available and the search terms and engines are listed so the results are repeatable or can be updated. There is a total of 211 available synopses on the DSS.
Policymakers normally pay attention to the costs and benefits of implementing a road safety measure and the DSS has made a major advance by developing the E3 calculator (Economic Efficiency evaluation). New standardised estimates of the costs of crashes and casualties have been developed working with EU member states and these have been incorporated into a flexible calculator accessed on the DSS. This enables users to estimate the economic efficiency of a measure by entering the programme costs and expected casualties avoided. Either specific or standardised costs and injury valuations can be entered. Further, 31 baseline estimates of economic efficiency have been generated and can be adapted by users.
Finally, the DSS also addresses the important area of serious injuries and the related societal costs. A definition of Abbreviated Injury Scale level 3+ has been adopted as a standard definition of serious injury however the comparability of various enumeration methods has been questioned. The DSS incorporates a comparison of the Methodologies with guidance fir future convergence. Furthermore, a detailed analysis of the societal costs of serious injuries has been prepared using the standardised values for EU 28. Finally, in-depth crash injury databases have been examined to identify the most important risk factors associated with serious injury.
