Construction And Simulation Of Continuous Cellular Automata Model For Urban Roads Based On Improved IDM Following Rule

Urban road traffic,as an important part of urban infrastructure,directly affects the operation and development of cities.However,urban road traffic also has many problems,which bring great challenges to the management and planning of cities.Traffic flow theory mainly studies and analyzes aspects such as traffic operation conditions and traffic flow characteristics,which has a very important contribution to solving road traffic problems.Among them,meta-cellular automata models are widely used in traffic flow theory research and microsimulation modeling with their flexibility and simplicity.However,the traditional cellular automaton is discrete in time and space and cannot realize the continuity of state change in the process of vehicle simulation.Therefore,a continuous cellular automaton model is proposed,which no longer divides roads into cells,but treats vehicles as cells and introduces numerical computation methods such as the following rule to realize the update of vehicle state,so as to realize the spatial continuity and make the simulation results more closely match the actual traffic flow situation.In this paper,based on the theory of continuum cellular automata model,we introduce the improved IDM following rule,and combine with the actual operation characteristics of urban road traffic,establish the multi-lane changing rule based on IDM following rule,and finally establish the continuous cellular automata model of urban road based on the improved IDM following rule.The main contents of this paper are shown as follows:(1)Based on the continuum cellular automaton theory,the IDM vehicle following model is introduced as the vehicle driving rule,so as to establish the single-lane continuum cellular automaton model based on the IDM following rule with continuous vehicle state change.In addition,combining with reality,certain improvements are made to the IDM following model by multiplying the braking term of the original IDM model by a hyperbolic tangent function about the difference between an appropriate sight distance and the distance between the front and rear vehicles,which avoids the phenomenon that the original IDM following model does not introduce the concept of driving sight distance and causes high-speed vehicles to start braking and decelerating too early when approaching low-speed vehicles at a long distance.The improved IDM follow-me model is more consistent with the actual road traffic vehicle driving scenario.(2)The single-lane continuous cellular automaton model based on the improved IDM following rule is extended to a multi-lane model.The IDM model is too absolute and deterministic to reflect the differences between drivers,and it is difficult for the simulated vehicles to change lanes during the simulation,so that the expected maximum speed,expected maximum comfortable acceleration,expected maximum comfortable deceleration and expected following distance of the IDM model are introduced into the random term to realize the simulation of driver heterogeneity.At the same time,based on the improved IDM following rules and the realistic scenario,we propose the adapted lane change rules,including collaborative lane change and deceleration yield mechanism,which makes the multi-lane continuous cellular automata model more consistent with the urban road traffic operation.(3)Based on the introduction of a multi-lane continuous meta-cellular automaton model with improved IDM following rules,the modeling and simulation of a three-lane intersection inlet section of an urban road is carried out,and the influence of aggressive and conservative driver heterogeneity on the traffic flow of the intersection inlet section is explored along with the simple application of the continuous meta-cellular automaton model based on improved IDM following rules.The results show that the overall trend is that as the proportion of aggressive drivers increases,the average speed of vehicles is higher and the average delay of vehicles on the roadway is lower;however,this rule is not absolute,and in mixed driver types where there is a certain proportion of aggressive drivers but not a high proportion,the effect of aggressive drivers on the overall operational efficiency of the traffic flow may be much less than the effect of heterogeneity between different types of drivers In addition,the heterogeneity of drivers’ driving characteristics is more significant in less restricted and less controlled roads,for example,for the same signal cycle at the same intersection,the average speed and average delay of vehicles during the green light period are more significant than those during the red light period.For example,for the same signal cycle at the same intersection,the difference between the average vehicle speed and average vehicle delay during the green time period is more significant than that during the red time period.