Research On Some Key Technologies For Traffic Accident Appraisal

As automotive industry has been developed very quickly, the amount of vehicles increased rapidly,which brings us the revolutionary change of our life. It gives people more chance to choose the transportation, and makes the traffic more easily and conveniently. But the development of automotive also gives us the disaster besides the high efficiency and rapidness that brings to us namely traffic accident. The traffic accident has resulted in the social harm because it endangers people's life and property all over the world.The automotive industry grows very quickly recently even though with a late starting. But the roadway improvement cannot catch the speed of automotive increasing. The traffic accident in China is more serious than others because of the bad base of transportation and management, there will be the most people died in the traffic accident. It is necessary to master the rules of accident, judge the duty of the accident, deal with the accident, and take the effective safety precautions to control and prevent the traffic accident, reduce the loss of life and property, and construct the harmonious societyAccident analysis can be defined as to explain the reason of the traffic accident, make clear the whole process, judge the responsibility of both parts, summary the experience and lessons from the accident, and setup the precautions to reduce the accident, with collected information, material and data. The accident appraisal is developed with the increase of disputation and dissension of the accident, and sanity of the laws. It can provide the scientific evidences to identify the duty of the both parties in the accident, and to revert the fact of the accident.The main research work involved in this paper is as following:1. To expatiate the ponderance of the traffic accident, to explain the definition of the traffic accident, analyze the status of the transportation safety in our country, to show the current research all over the world, and to emphasize the necessity and purpose of the traffic accident appraisal.2. The basic theories used in accident appraisal are discussed. The necessary knowledge used in the traffic accident analysis could not be limited to traditional science system. It must be integrated from different subjects. Because the knowledge system for the accident analysis is not complete well, the common knowledge used recently for accident analysis is including collision mechanics, vehicle movement characteristics, vehicle construct, and human body engineering. The basic contents of collision mechanics introduced in this paper. It includes Newton Laws, energy conversation law, momentum conversation law, effective collision speed, restitution coefficient, friction coefficient, sliding rate, plastic deformation, and the three phases of the collision.3. Accident trace is the important evidence in accident scene. The accident trace on site is the mark on the ground which produced by human, vehicle and goods and mark on the surface of vehicle, human and goods. This paper describes the function of the accident trace to analyze the accident, introduce the variety of the trace which includes vehicle body trace and road trace (tyre trace, disperse trace), analyze the cause, characteristics and the examination method. An accident case is used to demonstrate the importance of the trace for the accident appraisal. 4. Reconstruction method of 1D and 2D collision in vehicle accident are discussed in this paper. It demonstrates the usage of the energy conversation law and momentum conversation law to calculate the vehicle speed during the accident. It introduces the 1D collision and right-angle-side collision, and the mathematics model of 2D collision. It analyzes the calculation of vehicle speed during obverse impact, rear-end collision and side crash. It analyze the relationship between effective collision speed and plastic deformation and the usage to calculate the vehicle speed. The above method is used to analyze an accident case and verify the feasibility.5. Motorcycle has been the common transportation tool now. The traffic accident caused by motorcycle in China with high percentage compared with other countries. It has following characteristics: high accident rate because of the large quantity of motorcycle; high death rate because of bad stability and lack of protect facility of motorcycle. The characteristics and type of collision between motorcycle and automobile is analyzed in this paper. The speed calculation method is analyzed for three collisions between motorcycle and vehicle, these include motorcycle front to vehicle side, vehicle front to motorcycle side, and motorcycle and vehicle obverse collision. An accident case about vehicle front to motorcycle side is used to verify the calculation method.6. Pedestrian road traffic accidents is referred to the collision between pedestrian and vehicle. This accident is mainly caused by high vehicle speed, bad safety consciousness of pedestrian. It is stressed on the pedestrian accident characteristics in this paper. The effect of pedestrian height and vehicle outline on the movement after collision is analyzed. The movement after collision is divided into several phases and the effect factors is demonstrated. Several vehicle speed calculation methods are introduced in the paper. These methods include brake trace ,theoretical equation and experiential equation. The feasibility is verified by using pedestrian road traffic accidents.