Reporting bicycle accidents to police in the COST TU1101 survey data base: Cross-country comparisons and associated factors

Police crash reports are often the main source for official data in many countries. However, police sampling and data are known to be subject to bias, making the countermeasures adopted according to them possibly inefficient. In the case of bicycle crashes, this bias is most acute and it probably varies across countries, with some of them being more prone to reporting accidents to police than others. Assessing if this bias occurs and the size of it can be of great importance for evaluating the risks associated with bicycling. The following paper utilizes data collected in the COST TU1101 action. The data came from an online survey that included questions related with bicyclists' attitudes, accidents, and pattern of use of helmets. An average of only 10% of all crashes were reported to the police (minimum of 0.0% Israel and 3.37% Greece to a maximum of a 30% of Germany). Some factors associated with the reporting level were: type of crash, type of vehicle and injury severity. Finally, no relation was found between the likelihood of reporting and the cyclist's gender, age, use of helmet, and type of bicycle. The significant under-reporting justifies the use of survey data for assessment of bicycling crash patterns as they relate to crash risk issues such as location, cyclists' characteristics, and use of helmet and strategic approaches to bicycle crash prevention and injury reduction, which are discussed in the paper.