The causes and circumstances of a traffic accident are of fundamental interest, especially for legislators and researchers in the field of road safety, as well as car manufacturers and suppliers. GIDAS collects traffic accidents with personal injury reported to the police in the amount of up to 3500 individual pieces of information and systematically produced images, which are compiled anonymously in a case file. It is important that all data collected serve purely scientific purposes and are not used to determine the question of guilt like a police investigation. Only a limited amount of information on the occurrence of accidents, the course of accidents, injury mechanisms and consequences of traffic accidents can be analysed from official traffic accident statistics. In order to meet the research needs of legislators and industry, further, i.e. more in-depth information and data bases are needed. This gap is closed by specially equipped and trained survey teams collecting and anonymizing a subset of all traffic accidents with personal injury reported to the police at two survey sites in Germany, regardless of the police objective, according to purely scientific aspects and documenting them anonymously.

The survey is subject to a sampling plan, as a full 24-hour survey is not feasible. The survey times are divided into blocks of 6 hours each, of which 2 are served per day (midnight to 6 am and 12 pm to 6 pm or 6 pm to 12 pm and 6 pm to midnight). The division of the blocks alternates on a weekly basis and is also coordinated in a complementary manner among the survey teams. If an accident is reported via the police control center within a survey block, the teams consisting of technically and medically trained personnel drive to the scene of the accident.

Essential for a later reconstruction and analysis is the comprehensive recording of the entire circumstances surrounding the accident under consideration. To this end, information is obtained at different levels: the description of the course of the accident and the type of accident, the type of accident, etc. with sketches regarding Directions of travel, collision and end positions; a characteristic of the parties involved - medical data of the injured persons and, if applicable, technical data of their vehicles. The sequence of the rescue chain, the securing of the accident site and the flow of traffic at the time of the accident are also recorded.

The informative value, the extrapolation to Germany and the representativeness of GIDAS is based on the fact that the survey is a two-stage, stratified random sample in which the GIDAS accidents are drawn from the occurrence of all accidents in the survey area. The GIDAS survey will be carried out as primary surveys "in-time" and "on site" and the representativeness has been significantly improved again by adding the survey sites in 2023. GIDAS only records those traffic accidents that occurred within the respective survey area and the respective shift time and for which no more than 40 minutes have elapsed between the police report and the start of the journey of the technical team due to the operational readiness. The aim is to ensure that traces and thus important findings can actually be found at the scene of the accident in the accidents surveyed.

Data Privacy
Data protection is of extraordinary importance for such a scientific survey. In the GIDAS database, all information is available exclusively anonymously. For example, the names, addresses, dates of birth, etc. of the persons involved in the accident are not stored. The identification of specific accidents and their participants is prevented by not storing exact accident times, license plates, chassis numbers and other unique attribution characteristics. In all images, the faces of those involved, license plates, as well as special features such as imprints on vehicles are made unrecognizable.

The environment
Data protection is of extraordinary importance for such a scientific survey. In the GIDAS database, all information is available exclusively anonymously. For example, the names, addresses, dates of birth, etc. of the persons involved in the accident are not stored. The identification of specific accidents and their participants is prevented by not storing exact accident times, license plates, chassis numbers and other unique attribution characteristics. In all images, the faces of those involved, license plates, as well as special features such as imprints on vehicles are made unrecognizable.
It is regularly reviewed internally whether the methods used to protect this data meet the requirements of the Data Protection Regulation.

The Accident Participants
In addition to basic information on the height, weight and age of a person involved in an accident, data on driving licence ownership, any restrictions such as pre-existing conditions and stress factors, but also driving experience and distractions are important. A targeted questioning of those involved can provide further information about the accident. The influencing factors are examined with the respondents according to the situation. The consequences of the accident, i.e. the injuries of the persons involved, are also of central interest. The severity and type of injury, as well as the origin of it, are also recorded and documented. With the declaration of consent of the parties involved, injury diagnoses and treatment measures in the hospital can be included in the file. With the accident data collected and a sketch of the accident site including traces, a reconstruction of the course of the accident is later carried out. This looks at the initial situation and movements of the participants before, during and after the collision. Parameters such as gaze relationships and forces are also taken into account.

Since 1 July 2023, in addition to the Hannover Medical School (MHH) and the Traffic Accident Research Department at TU Dresden GmbH (VUFO), a team from the Ludwig Maximilian University and the Munich University of Applied Sciences (LMU/HM) has also been collecting traffic accidents as part of GIDAS, commissioned by the BASt or the FAT. In addition to the already existing survey areas around Hanover and Dresden, another one east of Munich was added. In total, the three sites together record approx. 2,000 traffic accidents per year, with approx. 1,000 traffic accidents attributable to the VUFO and approx. 500 traffic accidents each to the MHH and LMU/HM. BASt commissions and finances the teams from Hanover and Munich, while FAT commissions and finances the team from Dresden.

Road safety in Germany has reached a very high level in recent decades. The German In-Depth Accident Study (GIDAS), which has now been running for more than 25 years, has made a significant contribution to this. The findings and results obtained from this survey are continuously incorporated into the further development of road safety measures via the Federal Highway Research Institute (BASt). At the same time, they serve as the basis for new vehicle safety and assistance systems, which are made available to industry via the German Automobile Technology Research Association (FAT).

However, new technological developments and mobility concepts as well as social trends will influence the parameters in the field of road safety in the long term. Just a few examples of this are increasing electrification, automation and connectivity. These are already showing far-reaching consequences in the daily dealings of all road users in German road traffic.

In order to continue to assess the effects on road safety in advance through research and development and to be able to initiate measures at an early stage, adjustments are also required in the collection and evaluation of data within GIDAS.

To this end, the modules contained in GIDAS will be revised both in terms of content and methodology. At the beginning of 2023, key results of the further development work were implemented and implemented in GIDAS. In addition, competencies in the areas of infrastructure, psychology / people in transport and medicine will be strengthened and the project will be supplemented by new building blocks so that current and future questions can be answered. The results of specifically initiated research projects are used for this purpose. In addition, legal, methodological and organisational adjustments have been made in order to meet the high standards of quality and quantity, representativeness and innovation and to meet the requirements for answering future road safety questions.

The updating and adaptation of on-site accident surveys within the framework of GIDAS 4.0 are anchored in the Federal Government's Road Safety Programme 2021 to 2030. Further methodological adjustments will thus follow and be implemented in the coming years. FAT and BASt reaffirmed the continuation of the cooperation, which was considered successful by both sides.