Road Safety: A Similarity Analysis of the GIDAS Data and the Overall Incidence of Car-to-Car Accidents on German Roads

In this paper, the authors examine car-to-car accidents for similarities of the three accident data sources German In-Depth Accident Study (GIDAS), GIDAS-Pre-Crash-Matrix (PCM) and the German Federal Statistical Office (DESTATIS). The data from the Federal Statistical Office are compared with the GIDAS data in a descriptive analysis. Among other variables, accident type, accident locations and injury severity distributions are investigated. In the process, systematic deviations between GIDAS and DESTATIS are presented. In addition, a previously published methodology for the extrapolation of GIDAS accidents to the national statistics is applied on car-to-car accidents and the weighting factors for 36 different sections are calculated. When comparing GIDAS and GIDAS-PCM, statistical tests are presented and used to check distributions of accident types and collision speeds for similarities. One of the results of the analysis is the dissimilarity of collision velocities between the GIDAS database and the GIDAS-PCM simulation database in car-to-car accidents. The presented analysis method can be part of a robust simulative effectiveness assessment to evaluate the validity of the simulation results in relation to the overall considered accident dataset.