Study On The Minimum Trucks Security Following Distances On Longitudinal Slope Freeway

Freeway has a remarkable characteristic of high speed,convenience and high efficiency in transportation,which the development of economy.The freight capacity and volume of freeway are improving,But the accident rate of trucks is high,the accident rate is highest,the accidents of rear-end and accident are the most dangerous,the main reason is vehicles is insufficient.Therefore,it is necessary to research the minimum distance of long longitudinal slope,ensure the safety of truck and improve service quality of freeway.First of all,by reference driving behavior of trucks,the grew uphill and long downhill to make an effective definition;According to investigation result of the truck model of the freeway,the representative model of the truck is determined.Secondly,analyzing the influence of vehicle weight and the circumstances resistance of air and wheel rolling,the"slope-circumstances"acceleration a_s-c is determined.The minimum safety distance longitudinal slope are analyzed from four aspects of drivers,vehicle,road condition and traffic environment.And then,The longitudinal slope guaranteeing the model reliability and satisfying characteristics,the calculation model of the minimum distance of trucks.Reaction time t_f,maximum acceleration a_t and acceleration a_s-c to calculate distance of trucks.The results show that the TruckSim2016 of the vehicle simulation platform shows that the minimum safe driving distance can meet the safety requirements of the truck.Finally,based on the conclusion of the dissertation,it is significance to prevent the rear-end collision and reduce the property to put forward the measures from the climbing and downhill driving state of the truck respectively.