Extrapolation of GIDAS accident data to Germany and Europe

We investigate traffic accident data from project GIDAS (German In-Depth Accident Study). This project collects detailed accident data in two reference regions within Germany, Hanover and Dresden. For each accident with severely injured persons in these regions, the regular accident recording by police and medical staff is accompanied on site by a GIDAS team consisting of automotive engineers and accident researchers. The result is a very detailed data set that is, however, restricted to two particular regions. We develop methodology to extrapolate the influence of certain factors on the distribution of injury severity to other regions in Germany and Europe. The main problem is to take into account structural differences between the regions, such as relation between traffic on highways/country roads/inner-city roads, different vehicle types and so on. In particular, we have to compare discrete distributions over pre-defined classes of injury severity that may vary only by small amounts across regions.