Study On Optimisation Model For Road Signal Coordination Considering Fleet Compression

With the growth of motor vehicle ownership,the conflict between supply and demand in urban road traffic is becoming more and more serious.Signal coordination control is an important traffic management and control method in urban roads,and the discrete behavior of the fleet is an important factor affecting the effectiveness of signal coordination control.In this paper,the concept of "fleet compression" was proposed.And based on this,a unidirectional phase difference optimization model and a two-way signal coordination optimization model were established.The purpose is to make the fleet more compact and smooth in the process of driving,reduce its stopping and delay at the intersection,improve the coordination control effect,and enhance the practicability of the coordination model.The main elements are as follows:(1)The existing research results in the field of signal coordination control were reviewed,and the shortcomings of the green wave bandwidth maximum class method and the delay minimum class method in solving the problem of discrete fleets in coordination control were pointed out.To address the problem that the discrete behavior of fleets seriously affects the effectiveness of signal coordination control,a thesis on signal coordination control models considering fleet compression was carried out.(2)The impact of discrete fleet behavior on signal coordination control was analyzed,based on which the concept and method of fleet compression were proposed.From the perspective of delays generated by coordination,the impact of discrete traffic flow behavior on the effect of signal coordination control was analyzed by combining two scenarios of head stop and tail cut-off of the coordinated traffic flow upon arrival at the downstream intersection.A simulation analysis of the factors influencing the optimal compression time of phase difference was carried out.The results show that as the coordinated flow increases and the intersection spacing became larger,the overall delay curve of coordinated traffic was raised and the value of the optimal compression time became gradually larger.(3)The unidirectional signal coordination optimization considering fleet compression was studied.Firstly,the departure and arrival characteristics of the traffic at the upstream and downstream intersections were analyzed.Then,based on the traffic wave theory,the relationship between the number of stops and the compression time,and the delay and the compression time were derived to optimize the phase difference between the upstream and downstream intersections.Finally,four one-way signal coordination control schemes were designed from different perspectives.Simulations of the four schemes were carried out to compare the number of stops and delays of coordinated traffic flows,showing that the phase difference optimization model considering fleet compression can effectively improve the one-way signal coordination control effect.(4)A study of the optimization model for two-way signal coordination on roads considering fleet compression was carried out.With the nearest ideal phase difference between the actual phase difference in the upstream and downstream directions as the optimization objective and the corresponding constraints under different phase release modes,a two-way signal coordination optimization model with integrated optimization of phase difference and the phase sequence was established.Five consecutive signal-controlled intersections on Guyang Road in Zhenjiang City were selected as simulation cases,and the simulation results show that compared with the MULTBAND model,the scheme generated by the road two-way signal coordination optimization model considering fleet compression in this paper can effectively improve the signal coordination optimization effect,thus verifying the effectiveness and practicality of this model in road signal coordination control.