Estimating the potential benefit of advanced safety systems by simulation has become increasingly important during the last years. All over the world OEMs and suppliers carry out benefit estimations by simulations via computer models. Such simulations should, of course, be based on real world scenario such as the pre-crash phase of real world accidents. Several methodologies for building up accident scenarios have been developed in the past. This paper shows a new method for generating pre-crash scenarios directly from the reconstruction of the accident by using the software PC-Crash1. The new method was developed by the Medical University Hannover (MHH) and the Fraunhofer Institute for Transportation Dresden (Fraunhofer IVI). It is based on transferring all information (participant-, vehicle-, environment- and motion-data) from the reconstruction file into a scenario-database. In order to analyse the pre-crash situation of real-world accidents and changing boundary conditions (e.g. introduction of certain active safety systems), a socalled Pre Crash Matrix (PCM) was developed. Using the PCM philosophy and including 5 seconds before the accident in the crash analysis combined with the driving behaviours of the vehicles out of PC-Crash, it is possible to analyse, whether or not a sensor system would have been able to recognise the dangerous situation in time to avoid or mitigate the accident. Since intermediate simulation steps with several assumptions are rendered unnecessary, this new method, called TADS (Traffic Accident Database on Scenarios) ensures that there is no tolerance/deviation between the reconstruction and the scenario-database. Every reconstructed pre-crash phase of an accident can be directly imported to the scenario database. This paper will give an overview how TADS work and how it might be used by an example of heavy goods vehicles.