Integration Of Traffic Route Guidence And Signal Control Considering Traffic Dynamics

With the rapid development of the urban scale,the socio-demographic,and the auto-vehicle ownerships,contradictions between supply and demand of urban transportation resources are becoming increasingly con-spicuous.The increasing traffic demands and various traffic incidents also aggravated urban traffic problems.Therefore,it becomes important urgent problems in the following fields,including making full use of the ex-isting transportation resources,enhancing traffic operational efficiency,and making quick decisions in traffic incident conditions.In this study,the history and the development of vehicle route guidance systems and the traffic signal control systems are elaborated in detail.Accordingly,those most commonly used vehicle route guidance and traffic signal control strategies are modeled using the microscopic traffic simulation software,PARAM-ICS.Considering different control approaches,typical methods for each approach is selected.They are the fixed signal control,the adaptive signal control,and the regional coordinative signal control.Meanwhile,characteristics of different vehicle route guidance approaches are captured by multiple user compliance rate and various route guidance information update frequency.Using the Sioux-Falls network,a large number of simulation experiments are conducted to the combined vehicle route guidance and traffic signal control strategies.The most optimal combined strategies are selected considering varying network traffic situations.And the transferbility test shows good results.At the same time,starting from the analysis of the temporal and spatial characteristics of traffic inci-dents,the relationships between traffic incidents and vehicle route guidance,and between traffic incidents and traffic signal control are analyzed mathematically.It shows that,neither the area and duration of traffic incident,nor the public frequency of route guidance information,they were non-monotone to the network performance.More specifically,based on the simple examples applied in the study,the network performance of some specifically public frequency outperforms others.Further analysis were conducted via the PARAM-ICS simulation in 4 different traffic incident situations.It shows that actuated signal control outperforms the others in low traffic demand and the user compliance rate has limited positive relationship to the network performance.When the user compliance rate is higher than 75%,it causes inhibition of the better netwokr performance.Moreover,the study extends the Double Queue model to a new dynamic traffic network model consid-ering urban traffic signal control.The characteristics and the key properties of the new model are discussed,including the designed constraints,the first-in-first-out,and so on.A numerical case is applied to illustrate those traffic phenomenon.The results indicated that the signal based double queue model captures traffic dy-namic characteristics.Additionally,based on the extended model,the continuous optimal of dynamic traffic assignment and traffic signal control model is proposed and solved using GAMS/NLPEC after discretization.Numerical test result shows that this model describes the dynamic user equillibrium in an approaching way.This study also proposed a novel distributed signal control strategy,termed as the Double Pressure signal control strategy.Derived from the P0 signal control,which is proposed by Mike Smith,the Double Pressure signal control takes the downstream link carrying capacity into consideration.The so-called double pressures includes an endogenous pressure,which comes from the estimated exit-flow during a signal phase within the following cycle,and an exogenous pressure,which is a virtual pressure from downstream links,due to the finite link carrying capacity.The new strategy is proved to be capacity maximization and to be benefit for queuing stability.The numerical studies shows that the new strategy performs as expected.It outperforms the original P0 signal control,especially for incident situations.On the other hand,the influence of dynamic users' route choices on network performance is also tested via simulation.Finally,in order to evaluate the overall performance of different integration strategies,a macroscopic fundamental diagram based performance criteria is proposed.To take the Double Pressure signal control for example,it is integrated with different vehicle route guidance strategies considering different traffic demand,varying from nearly zero demand to over-saturated traffic demand.The new criteria is applied in both the normal traffic condition and the traffic incident condition.The test result shows that the new criteria provides reasonable performance evaluation,and the Double Pressure signal control performs in most situations.