RECONSTRUCTION OF AN UNUSUAL ROAD TRAFFIC ACCIDENT USING TWO DIFFERENT VERSIONS OF A SIMULATION PROGRAM Attila Iuliu GÖNCZI, Adrian CIPLEU, Liviu MIHON Abstract: In most of the cases of a road traffic accident reconstruction, the usage of traditional reconstruction methods represents the basic set of tools, but in an ever increasing number of cases, computer simulation is used for control the results or vice versa. In some cases, traditional methods, based on linear momentum conservation, energy conservation and assessment of deformation of the vehicles or experimental results of crash tests are not suitable because of the highly unusual character of the collision. The paper deals with one case of this type in which the pedestrian was cut in two parts. Keywords: road accident reconstruction, computer simulation, pedestrian, hitting speed, complete transection. 1. INTRODUCTION Road accident reconstruction is a very complex task in almost every case. In most of the cases of a road traffic accident reconstruction, the usage of traditional reconstruction methods represents the basic set of tools. Until about the late 1970s accident analysis were carried out using the conservation of the linear momentum and the angular momentum. The law of conservation of energy was only used on a small scale for calculations. In the decade of the 1980s and 1990s, the spectrum of the methods used for reconstruction began to broaden. At the beginning of the 1990s, the first complex reconstruction computer programs were developed. Today, in most of the cases, the traditional reconstruction and the methods based on simulation are used in parallel in order to reduce the level of uncertainty of the analysis. Nevertheless, in some cases, traditional methods, based on linear momentum conservation, energy conservation and assessment of deformation of the vehicles or experimental results of crash tests are not usable because of the highly unusual character of the collision. 2. A SHORT DESCRIPTION OF THE COLLISION A Peugeot 307 having two passengers on the front seats run on a rural two lanes road during night and hit a 30 years old pedestrian who was highly alcohol intoxicated (with a BAC of 2.55‰). As a result of the collision, a complete severance of the body of the pedestrian occurs. The upper half of the body was found in the car, in front of the right front seat, because the windshield was broken and penetrated by the head and the upper part of the body (in reality the upper part probably landed on the body of the passenger who seated on the right front seat of the car), while the lower half was found on the road, at a distance of about 55 meters from the back of the Peugeot stopped after the collision. There were neither skid marks nor yaw marks on the road, just some blood stains where the lower part of the body landed on the road and skidded until its stop. There were no signs found which could define the point of impact