Study Of Influencing Factors On Traffic Injury Severity Based On The NAIS

With the rapid development of the economy in China, the retention of vehicles is increasing fast, which may cause a great threat to the health and property of vehicle users. Nations built their own traffic regulations, which also continue to progress in recent 200 years, to improve the safety of the traffic according to the distinguishing features.In order to understand the distinguish traffic injury feature in China, the study gathers 1,764 traffic injury cases, including the injury severity, the information of passengers, vehicles, roads as well as the environment in the database of National Accident In-depth Investigation System, 32 variables in total. On the basis of the data validation, centralization and correlative between the variables, the age of the passenger, seating position, vehicle mass and other 13 variables were filtered for further study. The multinomial logistic regression method is applied to asset the influence of the 16 variables mentioned above on the injury severity score. The parameters su ch as goodness of fit, analogous R2 and others indicate that the model in the study has relative high prediction accuracy and through this model we can find the significant variable and its influence level.The regression results show that vehicle mass pla ys a significant role in critical injury. From the prospective of crash compatibility, simulation tests are designed to analyze factors that may influence the injury severity of car-truck rear collision. Vehicle models are selected in NCAC database accordi ng to the mass distribution in NAIS and verification is done. An orthogonal test is conducted to analysis the influence of relative velocity, overlap ratio, material strength and height of the rear end protection device of the truck on the intrusion of passenger compartment and driver injury parameters.The result shows that the accident characters an effectively influence the passenger injury severity and more factors are involved in more severe crash. Relative velocity, overlap ratio, material strength an d height of the rear end protection device of the truck can significantly influence the intrusion and the crash pulse to influence the injury parameters. Overall, the relative velocity and overlap ratio cause a larger intrusion more easily. Relative veloci ty and the material strength of protection device of the truck are more likely to influence the injury severity of the driver. More attention should be paid to the protection of the car-truck rear collision by revising related regulations.