Study On Optimization Of Bus Lane Network Design With Consideration Of Construction Period

Due to the high concentration and compact layout of China's urban development model,urban road resources are very tense.Against this background,the "bus priority"strategy is imperative.The setting of bus lanes is not only the prerequisite of "bus priority" but also the need of solving urban traffic congestion and promoting urban public services.However,the arrangement of bus lanes cannot be achieved overnight.On the one hand,the investment of funds should be considered;on the other hand,the negative impacts caused by the drastic changes of road resources should be taken into consideration.Therefore,the bus lanes are often set in stages and the traffic demand will also change in different periods.Therefore,this paper first determines the size of bus lanes,and solves the problem by using Random forest prediction method.Then,this paper considers the impact of bus lane setting on bus operation,and optimizes the capacity allocation and departure frequency of bus lines under the given public lane layout.The method uses the branch and bound method commonly used in integer programming.Considering the time-sharing,a two-layer model of time-sharing bus lane layout optimization is established.The upper model is a decision model of bus lanes.The model includes the bus departure frequency optimization model.The total travel cost of buses and private cars with different objective functions for different periods of time is the smallest.The lower model is divided into two sub-models,which are transportation mode partitioning model and traffic assignment model respectively.The method of dynamic traffic simulation is used to solve the traffic assignment model.A heuristic algorithm named bat algorithm is used to solve the bi-level programming model.Finally,taking Dalian Economic Development Zone as the research object,this paper determines the 30.4 km alternative bus lanes in the development zone and predicts the net size of the bus lanes is 14.644 km-20.92 km.The optimization results of the bi-layer model show that compared with the scheme of continuously setting up bus lanes,the optimization of bus lanes with time-sharing can get better results.From the perspective of road traffic flow,the setting of bus lanes can ease the congestion of urban traffic.In the longer run,the setting of bus lanes can change the travel habits of tra'velers and has positive significance to the development of urban public transport.