Optimizing For Urban Road Segment Maintenance Projects With Consideration Of Mixed Traffic

Urban road maintenance operations will inevitably make some influences to the road traffic. By optimizing maintenance projects, it can optimize maintenance effects, maintenance costs, and traffic influence, respectively. And By optimizing maintenance projects, it can give more benefits to the road agency, the government and the road users. So it is a very important work.A review of studies on work zones optimization is made from the aspects of traffic capacity, traffic accident and vehicle speed control in work zone. Then a summary and analysis is made from three aspects of urban road maintenance in China, traffic influence from work zones, and principles and measures of traffic control and management. Based on these studies, a maintenance total costs model is given.The maintenance total cost model is built up from three parts of maintenance cost, delay cost and traffic accident cost. In order to accurately reflect real maintenance work, some adjusting parameters are made from work in night, maintenance sorts, traffic accident in night, different traffic modes and different travel costs.The key of total cost model optimization is to accurately compute traffic delay. Firstly, a mathematical model is built up to compute the traffic delay in mixed traffic. The study shows that it is difficult to accurately compute traffic delay by using mathematical model. Therefore, a traffic simulation method is given to resolve this problem.A road segment maintenance simulation model is built up by using VISSIM software. Based on calibrating the parameters of driving behaviors, traffic delay in work zones is calculating accurately. The resorts show that it is feasibly to compute traffic delay in mixed traffic by using traffic simulation method.In order to optimize maintenance projects, this study optimizes the total cost model. A"Trail-and-Error"method is given to optimizing the six maintenance projects with a numerical example. And optimal work zone length, optimal work starting time, optimal work duration time and optimal total cost are computed. The conclusion shows that it is possible to reduce the total cost through set the work starting time and work zone length. Maintenance in night also can reduce traffic delay evidently, and saving the total costs.