Studies On The Safety Of Basic Freeway Session

With the development of freeway in our nation, the loss of people property and lives caused by traffic accidents became more and more large. Basic Freeway Section is. one important composition of freeway, which safety level embodied the safety of vehicle operation. Based on the micro-traffic flow theory, the paper put forward the conception of driving risk, and then adopted improved-additive calculational methods, and used Imge-proceesing technique, finally set up the Safety Evaluation Methods used to audit the safety level of Basic Freeway Section.Firstly, according to the vehicle dynamics and the safety restriction, the paper deduced the safety operation speed under the state of car-following and lane-changing. Secondly, the factors that affected the safety of vehicle operation, then the operation speed and critical safety deceleration were chosed to evaluate safety level of vehicle operation on the road section. At the same time, according to the people's physiologic and psychologic responses under different accelerations, and the results caused by different speeds under traffic accident, the operation risk model was proposed. Thirdly, considering the characteristics of micro-traffic safety research, the metods of collecting traffic data was founded. By the imaging-proceeding technique, the moving vehicle indentifcation, operation tracks, simplify, coordinate conversion in an image were proposed, so the vehicle planar information at different time and different space were obtained. And then the real-time operation speed and safety deceleration were calculated. Finally, by analizing the experiment data, the paper gived an example applying the method, and the average index of vehicle operation risk was used to evaluate the safety level of Basic Freeway Section.The safety appraisal method mentioned above was based upon the micro-driving characteristics, so it can be applied to evaluate the real-time prone dangers of moving vehicles on Basic Freeway Section. When there was short of traffic accident data, the method can also be used to evalute the safety of Basic Freeway Section, which was better than traditional methods.