Study On Safety Evaluation Based On Road Conditions Of Freeway

Along with our country，s highway construction rising prosperity, highway trafficaccidents also shows growth trend and more serious, because of the highway traffic flowconcentrated, truck load large and high speed. So the highway traffic safety research isimperative. The highway safety evaluation is one of the important means of safetyresearch that can do the accident risk assessment and prediction. The freeway safetyevaluation of road conditions is a system science, which could reduce traffic accidentscaused by risk factors by reasonable analysis of the objective conditions.Highway traffic environment is a driver-vehicle-road (environment) system which isdynamic and circulation. In the system, various factors is influence and contact eachother. If we only analysis the single factor, sum up, it is not scientific. We think, that theinfluence of road conditions to the traffic safety is based on the impact of road design ondriver. It is rare to road design unreasonable lead to the occurrence of traffic accidentsdirectly in physical mechanics theory. On the basis of effecting on drivers psychologyonly, leading to pilot error, road conditions can cause traffic accidents. Therefore, basedon traffic psychology, the psycho physiological research of drivers，driving changes inthe environment is one of the key points. The another focus is comprehensive evaluationmethod research based on AHP.The article firstly analyzes the characteristics of Expressway accident and accidentsites, to find out the accident law, Then analyzing the influence of road condition factorson driver’s psychological and physiological. In this researching, we analyzes therelationship between the curve radius and the driver psychological changes, and toestablish a mathematical relationship model between the longitudinal slope gradient andslope length and the driver psychological changes, and put forward the "probably trafficaccident rate" concept, to determine the probability of the accident; Then we researchcomprehensive evaluation system based on AHP, and in this study established theevaluation index method of the specific assignment, 9 scale method of judgment matrixand" condition of road safety index CRSI." concept; Finally using Visual Basic languageestablish the road safety evaluation system, which including the design parameters database, specification test, comprehensive evaluation.