Age-based medical screening of drivers in Switzerland: an ecological study comparing accident rates with Austria and Germany.

BACKGROUND: In Switzerland, as in various other countries throughout the world, elderly drivers have to pass a medical screening assessment every two years to keep their driver's licence. The scientific literature shows no clear evidence that these policies improve road safety. This study evaluated the effects of the Swiss screening policy by comparing the accident and injury rates of elderly road users in Switzerland with those in Austria and Germany, two neighbouring countries without systematic age-based screening policies. The aims of this study were to examine if the screening policy is associated with a reduced risk of elderly car drivers causing serious accidents (research question 1) or with an increased risk of elderly pedestrians or (e-)cyclists being seriously or fatally injured (research question 2). METHODS: In all three countries, data on accidents were taken from official statistics based on police reports and mileage data from national mobility surveys. An accident was defined as serious if at least one person is seriously or fatally injured in it. Accident and injury rates were calculated using distances driven and population size as measurement of exposure. Multiple Poisson regression models were used to examine the association between the Swiss policy and the accident or injury risk of elderly persons. RESULTS: We found no association between the screening policy for elderly drivers in Switzerland and their risk of causing a serious accident (incidence rate ratio [IRR] 1.24, 95% confidence interval [CI] 0.79-1.94). Contrary to other studies, however, the Swiss policy was not associated with an increased risk of elderly pedestrians (IRR 1.16, 95% CI 0.80-1.68) and (e-)cyclists (IRR 0.79, 95% CI 0.56-1.12) being seriously or fatally injured. CONCLUSIONS: The intended positive effect of the Swiss screening policy on accident rates of elderly drivers could not be demonstrated in this study. These findings serve as a basis for discussion on how to proceed with the policy in the future.

A systematic cost-benefit analysis of 29 road safety measures.

Economic evaluations of road safety measures are only rarely published in the scholarly literature. We collected and (re-)analyzed evidence in order to conduct cost-benefit analyses (CBAs) for 29 road safety measures. The information on crash costs was based on data from a survey in European countries. We applied a systematic procedure including corrections for inflation and Purchasing Power Parity in order to express all the monetary information in the same units (EUR, 2015). Cost-benefit analyses were done for measures with favorable estimated effects on road safety and for which relevant information on costs could be found. Results were assessed in terms of benefit-to-cost ratios and net present value. In order to account for some uncertainties, we carried out sensitivity analyses based on varying assumptions for costs of measures and measure effectiveness. Moreover we defined some combinations used as best case and worst case scenarios. In the best estimate scenario, 25 measures turn out to be cost-effective. 4 measures (road lighting, automatic barriers installation, area wide traffic calming and mandatory eyesight tests) are not cost-effective according to this scenario. In total, 14 measures remain cost-effective throughout all scenarios, whereas 10 other measures switch from cost-effective in the best case scenario to not cost-effective in the worst case scenario. For three measures insufficient information is available to calculate all scenarios. Two measures (automatic barriers installation and area wide traffic calming) even in the best case do not become cost-effective. Inherent uncertainties tend to be present in the underlying data on costs of measures, effects and target groups. Results of CBAs are not necessarily generally valid or directly transferable to other settings.

The European road safety decision support system on risks and measures.

The European Road Safety Decision Support System (roadsafety-dss.eu) is an innovative system providing the available evidence on a broad range of road risks and possible countermeasures. This paper describes the scientific basis of the DSS. The structure underlying the DSS consists of (1) a taxonomy identifying risk factors and measures and linking them to each other, (2) a repository of studies, and (3) synopses summarizing the effects estimated in the literature for each risk factor and measure, and (4) an economic efficiency evaluation instrument (E3-calculator). The DSS is implemented in a modern web-based tool with a highly ergonomic interface, allowing users to get a quick overview or go deeper into the results of single studies according to their own needs.