Study On The Work Zone Scheduling Problem In Urban Road Network Considering The Traffic Day-to-day Characteristics

The existence of work zones often involves lane closures,causing the capacity reduction,aggravation of urban traffic congestion,increases in travel cost and other disadvantages.When many projects on the urban road need to be constructed,the different sequences may have varying degrees of impact on the whole urban traffic network.Although this effect is inevitable,relevant decision-makers can select the appropriate sequence to minimize the impact of work zones construction on the urban traffic.In recent years,all kinds of cities in China are in the stage of large-scale urban transportation infrastructure construction,however,due to the disorder of urban road construction at present stage,traffic congestion during construction is becoming more and more serious.Therefore,in order to reduce traffic delays during the construction period,the scheduling of work zones has become an important issue in the construction of the urban road.The existing researches mainly focus on the problem of short-term construction and use the static traffic assignment to analyze the distribution of traffic flow under the construction background,so the optimal construction sequence is determined by calculating the size of traffic delays.For the long-term construction,it has some shortcomings in both technical and economic aspects.There are fewer studies focusing on the problem of long-term construction scheduling,and they are also mainly based on the UE static traffic assignment.The characteristics of the day-to-day network traffic evolution caused by the closed road are not considered.Although there is a unique research about considering the distribution of day-to-day traffic flow,it obtains traffic transfer rate between different paths mainly through the questionnaire survey.So it exists some limitations in the determination of sample size,the selection of representative sites and the application size of the network.Therefore,in order to analyze traffic delay accurately and obtain reasonable work zone construction sequence,it is necessary to adopt a new analytical method to conduct researches.Day-to-day traffic assignment method is proposed for the first time to analyze the day-to-day evolution of traffic flow during the long-term construction period,then the work zone scheduling optimization model is established,and the optimal scheduling is determined by comparing the total impedance increment in different construction sequence.First of all,in view of the diversity of trip conditions,this paper proposes the work zone scheduling model and gives the solution algorithm under the condition of the homogenous traffic flow assumed to be the fully rational travelers.Then,travel rules of the fully rational travelers and the bounded rational travelers are defined respectively under the condition of mixed rationality,and a traffic day-to-day assignment model of heterogeneous traffic flow under construction background is established.Based on this model,this paper proposes the corresponding work zone sequence optimization model and gives the algorithm.Finally,under the condition of mixed rationality,this paper establishes the day-to-day traffic assignment model considering stochasticity under the background of the construction and proposes the corresponding construction sequence optimization model.Through simulation analysis for the numerical example,the results show: under the condition of homogeneous traffic flow with completely rational travel,a work duration threshold exists,and increasing the work durations will no longer change the optimal work zone scheduling after this threshold.When the work duration is longer,the travel impedance calculated by using the day-to-day model and UE model has a negligible difference.It may increase the problem complexity if it continues to use the day-to-day traffic assignment model.In addition,the number of work crews and model parameters have also an obvious influence on the optimal work zone scheduling.In practice,a variety of factors should be taken into account to determine the number of the work crews and the value of the model parameters.Under the mixed rational condition of the coexistence of the fully rational travelers and the bounded rational travelers,the existence of limited rational travelers will increase the fluctuation of day-to-day traffic evolution and change the optimal work zone scheduling.The bounded rational behaviors in different degree will make the optimal construction order changed,from the point of traffic impedance,subjective cognition deviation coefficient has little effects on the fluctuation of traffic impedance,but with the increasing of this parameter,the network total impedance will increase gradually.As for the cognitive threshold coefficient,the day-to-day fluctuation of the traffic impedance decreased gradually with the continuously increasing of this parameter.Under the condition of mixed rationality considering the stochastic trip environment,the optimal construction scheduling will be changed by the different randomness of the traveler and the proportion of the traveler with bounded rationality.For the daily traffic impedance,its fluctuation is greater with the increasing of stochasticity.