| The characteristic of vehicle and pedestrian crashes accidents have become diversified because of the complexity of road traffic environme nt, different analysis methods have difference in atypical accidents application, through the research of analysis method for vehicle and pedestrian crashes, the advantages and disadvantages of different methods are compared, different methods application of accident analysis are discussed, it is great of significance to improve the accuracy of speed evaluation.Firstly, a total of 683 vehicle and pedestrian crashes accidents were collected, including 20 statistical indicators on the accident basic information, pedestrian data, vehicle data, road and environment data, accident types. According to the overall distribution of the accident, characteristics of speeds, the crash positions and analysis results of different accident types showed that the speeds were normal distribution, the prone crash positions were different in three vehicle types, no braking trace distance accidents form the largest number of accidents, accounting for 81.4%. Logistic regression models of the risks for pedestrian fatality, slight injury and serious injury models were developed in terms of vehicle impact speed and pedestrian age. By accident type and extent of pedestrian injuries analysis co ncluded that due to the different spot traces, accident analysis methods selected should have strong target.Secondly, a detailed theory analysis of accident reconstruction methods based on accident spot traces, including the vehicle information, pedestrian information, and video information were conducted. The contrast analysis of vehicle track, pavement fallout, windshield damage, pedestrian throw distance, video information about accident were conducted based on the model theory, input and output parameters and analysis process. Also the methods of based on vehicle track include conventional braking trace distance method, Crashview and PC-CRASH, the characteristics and difference were discussed separately based on the vehicle dynamics model, tire ground mechanics model, accident reconstruction process.Thirdly, the applicability of practical application of different accident reconstruction methods were analyzed in detail. The practical applications scope for all kinds of methods were illustrated after the analysis of the constraints,the difficulty and accuracy of collection of scene data required for the model, calculation error rate and simulation results. The methods advantage and disadvantage were discussed about different parameters of pedestrian, vehicle and road environmental. The results show that the methods based on vehicle track calculate accurately and widely used, the main application are Crashview and PC-CRASH, due to the strict conditions that remaining methods applied, they can only be applied in specific cases. Then a variety of atypical accident type reconstruction methods are carried out.Finally, Uncertainty theory was expounded and applied in the accuracy of the different methods of accident reconstruction. Through the uncertainty calculation of specific accident case,the applicability of different methods were compared and verified. |
