22nd ESV, Washington, 2011

The casualty risk of drivers according to their exposure is usually defined taking into account the frequency of use of road infrastructures. However, this information does not classify drivers according to their characteristics (age, sex, etc.), which does not enable effective measures for each driver profile to be adopted.

The objective of this study is to define an index able to indicate the risk according to exposure of motorcyclists. Motorcyclists are classified into different profiles taking into account not only the drivers’ characteristics but also the type of motorbike they drive. This classification make it possible to discover which groups are more exposed to the risk of having a fatality, enabling prevention measures focused on these kinds of drivers to be adopted.

To perform this study a complete database is necessary and so an existing database which contained information about the victims and the motorbike they drive is merged with another database which contains information about the mileage for each kind of motorbike. By merging data from both databases, a complete database is created. The next step is to calculate the Index of Risk according to Exposure (IREx) for each profile.

The innovative aspects of this methodology are basically two: IREx assesses the risk taking into account the mileage of the vehicle, and this assessment is performed separately for each profile of driver and type of motorcycle. The results of the study make it possible to observe some tendencies from which the investigator is able to draw conclusions which can be helpful in adopting measures to diminish the number of motorcyclist fatalities.