Analysis Of Traffic Flow Characteristics Affected By Traffic Flow Guidance Area Of The Entering Approach At Signalized Intersection

At present,the relevant fixed standards of urban traffic are used to design the entrances of intersections,however,which are difficult to meet the complex surroundings of the roads.The vehicles of the entrances can't change lanes in time and are forced to lane changing or wait for timing change frequently because of the unreasonable length of the traffic flow guidance area(main guidance arrow setting area),which may result the road congestion increasing and be waste of the road resources of space and time.Therefore,it's necessary to the detailed analysis of the influence of traffic flow guidance area on traffic flow which can provide the reference for the actual road traffic design and management.Firstly,we focused on the characteristics and conditions of traffic flow steering,and analyzed the characteristics and their classification of driving behaviors through the extensive review of literature data;while a detailed discussion and the summary of the rules of the exit road model were conducted,we summarized the application value of cellular automata(Cellular Automata,referred to as CA)in the field of traffic flow research and introduced the forced lane-changing model for the entrances.Then,the entrance lane is divided into three zones,which are respectively free lane changing area,direction changing area(the dashed line area of guiding arrows)and forbidden lane changing area(the guiding line area of the lane-changing),considering the lane changing characteristics of vehicles in different areas of the entering approach;the forced lane change probability is introduced to represent the driver's desire to change lanes by considering the driver's lane-changing pressure;based on existing the cellular automata models and adding signal control factors,a two-lane cellular automata traffic flow model is presented considering safety lane change and unsafe lane change conditions,which are made of different following and lane-changing rules corresponding to different sections of the road.Finally,the numerical simulation was performed by changing different road traffic parameters under different vehicles' arriving and steering ratios using MATLAB programming software.And on the basis of traffic flow micro-data,the study discusses the changing rule of the traffic flow characteristics effected on the traffic flow guidance area,such as analyzing the impact of the arrival rate of vehicles on the traffic flow of the entrance roads,vehicles' lane-changing,the changing rules of the speed and density in the roads,and time-space diagram of the vehicles' evolution.The results show that the length of the flow guidance area has a greater impact on the traffic flow because of the large traffic volume of the entrance roads.Especially,the inappropriate length of the traffic flow guidance area is not conducive to the vehicle's steering and lane-changing.However,the lanes' space and time resources are wasted with the excessively long,which is not conducive to the improvement of the efficiency of the entering approach.