Simulation Of Traffic Flow On Ice And Snowfall Road With Possible Accidents Using CAM

The temperature in most parts of northern China is relatively low in winter.When snow falls,the road surface is prone to snow and ice.These not only reduce the road traffic efficiency,but also seriously threaten the safety of driving,resulting in the increase of traffic accident rate.Traffic flow simulation is an important tool for research on the problem of transportation.It can provide more accurate decision-making basis for management and control measures of ice and snowfall road through the simulation of road traffic flow under snow and ice conditions,thereby reducing the probability of traffic accidents and improving road traffic safety.At present,the research on road traffic safety under adverse weather mainly focuses on the aspects of macro statistical analysis and control,vehicle dynamics analysis and so on.While few studies were related to optimization of management control measures based on the analysis of mechanism characteristics with the help of micro models of traffic flow,and less related to the situation of longitudinal slope section.Based on these,through analyzing impact of snow and ice on pavement characteristics,vehicle characteristics and driver,and combines vehicle force and driving behavior under different road geometry parameters,a cellular automaton model(CAM)of possible traffic accidents on ice and snowfall road taking one-way two-lane road as an example is established.Then this paper explored the possible rear-end and side-slip accidents on ice and snowfall road as well as the characteristics of traffic flow through simulation experiments,proposed refined management and control strategies to reduce the probability of traffic accident,and provides specific decision-making recommendations for traffic management and control.At the same time,the simple analysis and prospect were carried out in conjunction with the development of future intelligent transportation technologies such as internet of vehicles.The main work can be summarized as the following aspects:(1)Analyze the impact of snow and ice on the main parameters of road traffic.The basic concepts of snow and ice were explained.The effects of snow and ice on pavement characteristics,vehicle characteristics and drivers were analyzed at the system level.And the relationship model of pavement characteristic was established.At the same time,the influence of road geometric linear parameters on vehicles and drivers was analyzed.(2)Analyze the vehicle dynamics behavior of possible accidents under snow and ice conditions.In this section,the influence of road friction coefficient on vehicle braking performance and vehicle kinematics model under different road geometric linear parameters was analyzed,and the specific conditions were studied,which include rear-end collisions and side-slip accidents that may occur when the vehicle was driving on ice and snowfall road in depth.The micro-scale dynamic model of possible traffic accidents under snow and ice conditions were established so as to provide research basis for the establishment of specific CAM later.(3)Establish CAM for traffic flow of road with possible accidents under ice and snow.Based on the Na Sch(Nagel-Schreckenberg)model,CAM with possible traffic accidents under different road geometric linear parameters in snow and ice environment was established by improving the basic model combining the characteristics of traffic flow of ice and snowfall road.The characteristics of traffic flow and probability of traffic accidents on the ice and snowfall road were analyzed through simulation tests.(4)Carry out optimization research of management and control measures for ice and snowfall road.Aiming at the problems of road traffic safety caused by snow and ice,a simulation test was conducted taking a one-way two-lane highway as an example.The research was carried out to optimize the measures for different geometrical linear parameters of roads from the aspects of increasing pavement friction coefficient,traffic management and control and the applications of intelligent transportation in the future,and specific measures were proposed for road traffic management under snow and ice condition.