Working Schedules Optimization In Urban Roads Renovation Activities

The cost of urban road renovation is high and will have a negative impact on urban traffic operation,so it is very important to make a scientific and effective maintenance scheduling plan.However,the existing research on road renovation scheduling problems has many shortcomings in problem modeling and traffic impact assessment,which makes the corresponding methods difficult to meet the practical needs.In view of this,this paper comprehensively considers all aspects of factors and constraints,establishes an integrated optimization model of urban road renovation work zones and crews scheduling,gives an effective algorithm to solve the problem,and verifies the method with a numerical example.The main innovative work of the paper is summarized as follows:(1)An integer programming model is constructed to jointly optimize the urban road renovation sequence and crews scheduling.In addition to traffic delays,construction crews costs,equipment movement costs and duration costs are also taken into account in the objective function of the model.The constraints considered by the model include the number of crews,time limit,construction behavior,logical constraints,etc.The unbalanced evolution process of road network traffic flow during road renovation is described by a more reasonable day-to-day traffic assignment model.(2)Dur to the computational complexity of the problem,a two-stage heuristic solution algorithm is proposed by decomposing the original problem into two sub-problems of crews scheduling and road renovation sequencing.In the first stage,four improved heuristic algorithms are given based on genetic algorithm,tabu search and simulated annealing rules to obtain the crews scheduling plan with the lowest operating cost.In the second stage,an improved compass search algorithm was used to optimize the start date of each task in order to minimize the cost of travel delay for passengers.The results of a small-scale example show that the proposed first stage algorithm can quickly obtain the exact solution of the crews scheduling.(3)Three examples are designed based on Sioux-Falls network: centralized,uniform and mixed.The results show that all the four heuristic algorithms can solve the problem effectively,and the tabu search algorithm incorporating periodic simulated annealing rules has the best effect.The adjustment and optimization of the start date can further reduce the travel delay of passengers,which indicates that the second stage algorithm is necessary.The assumption of early start and continuous construction not only helps to reduce the difficulty of solving the problem,but also helps to get a satisfactory solution.