Study On Safety Evaluation And Optimization Of Expressway Interchange Exit Ramp

China’s transportation industry is developing rapidly,and freight traffic is also increasing rapidly.These developments put forward higher requirements for the safety of the road transportation industry.As an important node of traffic conversion,expressway interchanges play a vital role in the safety and efficiency of the entire road transportation industry.According to a large number of data at home and abroad,about30% of accidents on highways occur near interchanges,and the number of exit ramp accidents is twice that of import ramps.Therefore,the expressway interchange ramps are separated.A safety evaluation study is necessary.This paper first analyzes the types and causes of accidents on interchange ramps at interchanges,studies the relationship between people,vehicles,and roads and operational safety,and explores the factors that have the greatest impact on traffic safety,focusing on the coordination of operating speed,Three-dimensional linear continuity,line-of-sight,deceleration lane length of four factors were quantitatively analyzed,AHP analytic hierarchy process was used to assign weights to several factors,and the safety assessment of the expressway interchange ramp was established model.This model can not only be used for ramp safety evaluation,but also use this model as the fitness function of the genetic algorithm below to prepare for the optimization of the genetic algorithm.Then,the genetic algorithm is briefly introduced,and the feasibility of applying it to the safety optimization of ramps is analyzed.Combined with the engineering example,set the corresponding boundary conditions and constraints,determine the value range of the variable,consult the relevant literature of the genetic algorithm,set the corresponding parameters of the genetic algorithm,refer to the genetic algor ithm’s calculation process,and perform genetic operations on the engineering example,And finally get the corresponding parameters after optimization.Finally,the trucksim simulation software was used to simulate the exit ramp before and after optimization.Four indexes affecting the vehicle’s running stability,including body roll angle,wheel vertical load,lateral acceleration,and yaw rate were proposed.The change of each index value to verify whether the vehicle’s running stability has been improved,in order to verify the reliability of the optimized operation in this paper.The final result shows that genetic algorithm can be applied to ramp safety evaluation and optimization.In the actual production process,it can become a new technical method for designers to conduct ramp safety evaluation and optimization.