Research On Signal Coordination Method With A Work Zone On The Road

In recent years,with the growth of traffic demand,more and more construction projects are built on freeways and urban road segments.In the urban road segment,there are numerous work zones,and the existence of these work zones will affect the probability distribution of the vehicles,speed,the arrival rate of traffic flow,the queuing length and the queuing time,these factors will further affect the coordination scheme of signal intersections.However the existing coordination theories do not consider the related factors that affected by the work zone.When there are work zones on the road segment,the results of arterial coordination scheme will be inaccurate,and keep using the scheme will even cause more traffic delays.Although many scholars have studied the work zone,most of them focused on the freeway work zone,and there are few studies on the urban work zone,the study on the signal control under the influence of the urban work zone is limited.This paper focuses on the arterial coordination method under the influence of the work zone on the urban road segment.Firstly,the influence factors and mechanism of the road segment work zone on the traffic wave are analyzed through the study of the traffic wave propagation profile.Then based on the analysis of the changes on the traffic wave type,wave speed and propagation time,the traffic wave model is proposed.Through the proposed model,the calculation method of queuing delay can be obtained under the influence of the work zone on the urban road segment.According to the calculated queuing delay,a bi-objective arterial coordination model is proposed.The main conclusions of the study are as follows:a new type of traffic wave(deceleration wave)will generate at the upstream of the work zone.At the same time,the discharge wave and departure wave at the upstream intersection of the work zone will be affected by the deceleration wave,so the wave speed and propagation time will change significantly.If the discharge wave meets the deceleration wave,the maximum queuing length and the number of secondary queuing vehicles will increase.If the departure wave meets the deceleration wave,the number of secondary queuing vehicles will also increase.The queuing wave,discharge wave and compression wave on the downstream intersection will all be affected by the deceleration wave,and have different speeds in different locations.When there is no work zone on the road segment,lane blockage phenomenon can only occur when the intersection is widened.However,for the intersections with a road segment work zone,lane blockage phenomenon may occur even for the un-widened intersection.The MAPE of the proposed traffic wave model is about 20%,indicating that the model can capture the real traffic wave propagation situation.And the timing scheme based on the proposed arterial coordination model can greatly reduce the average delay and queue length of the arterial,indicating that the model has a good optimization effect.