The Problem of the Comparability of Road Accident Data from Different European Countries

(1) Background: The number of casualties due to car accidents in Europe is decreasing. However, there are still very large differences in the levels of road safety between countries, even within the European Union. Therefore, it is vital to conduct reliable international analyses to compare the effectiveness of actions taken to prevent road accidents. Information on the number of accidents, injuries, and fatalities can be found in various databases (e.g., Eurostat or OECD). In this paper, it is clearly shown that data on car accidents and the resulting injuries are not comparable between different countries, and any conclusions drawn using these data as their basis will be erroneous. (2) Methods: The indicators of the number of car accidents, injured people, and fatalities in relation to the number of inhabitants were determined, then their distribution and mutual correlations were examined for a group of selected European countries. (3) Results: There is no correlation between the indicators of the number of car accidents and injuries and the indicator of fatalities. An assessment of road safety based on these indicators would result in inconsistent and ambiguous conclusions. (4) Conclusions: It has been empirically shown that data on the number of car accidents and injured people from different countries are not comparable. These conclusions were verified by providing examples of the definitions of an injured person used in different countries. This paper clearly indicates that any international comparisons can only be made based on data regarding the number of road accident fatalities.