Research On Safety Evaluation And Improvement Strategies Of Freeway Traffic Flow

Traffic safety problem is a worldwide puzzle which will coexist with human being for long and have an extensive influence on sustainable development of our society. As an essential portion of transportation system, the construction and operation of freeway have a history no more than twenty and character quite differently in operation safety with developed countries, higher accident and fatality rate. This thesis mainly studies on how to appraise traffic performance safety of freeway and advance corresponding measurement to improve freeway safety.The safety effecting factors of freeway operation include human, vehicles, road and environment and management etc. The freeway operation safety evaluation is the basis of freeway operation safety management. Based on the total investigation of some freeways of China, the paper brings forward the model between the side friction and the equal accident calculating economic loss. Based upon the model framework, it puts forward the safety evaluation standard of the freeway traffic flow.In this research, the traffic parameter data inspected by the induce loops, the scene investigation data and the traffic accident data of some freeways are utilized to analyze. As for the safety assessment of the on-time traffic, the driving risk index is used to express the speed and speed diversion.The freeway operation safety assessment and standards of the on-time traffic performance on uninterrupted flow and interrupted flow admixture condition are modeled on the performances.As traffic parameters interrelate with operation risk, characteristic of orderliness and dynamic, so freeway traffic management contain two parts: static management and dynamic management. The relation between operation safety and operation speed is the core of static management, and speed control is the effective means of static management. Average speed is the key of speed control method, V85 and V10 acting as the upper speed limit and minimum speed limit.Dynamic traffic management has two categories: traffic management on uninterrupted flow condition and traffic management on interrupted flow condition. The latter investigates the traffic control method based on speed control and lane management. At last, the paper takes a example to analyse.