Route Optimization Method Of Flex-Route Transit Considering Traffic Conditions

In recent years,China’s social and economic development has continued and the process of urbanization has continued to advance.The resulting problems such as traffic congestion and urban air pollution have affected the living environment and quality of life of urban residents.Although the development of conventional public transportation can alleviate the increasingly serious traffic pressure in the city and reduce the pollution of automobile exhaust emissions,in the new urban area with low travel density,the conventional public transportation is difficult to adapt to the travel characteristics of the residents of the new area.Therefore,flexible public transport such as variable-route bus emerges as the times require,which takes into account the stability and low cost of conventional bus and the flexibility of demand-responsive bus,and has become a key link to promote the gradual improvement of urban public transport system.Due to the flexibility of the variable route bus,it is particularly important for the system to consider the traffic conditions to dynamically plan the vehicle path during operation and scheduling.Firstly,the development and research status of variable-route public transport and dynamic route optimization are reviewed.According to the characteristics of variable-route public transport system composition and operating rules,it is proposed that variable-route public transport should update road traffic information at key points,and carry out A path optimization method for dynamic adjustment of vehicle paths.Secondly,the dynamic route optimization model of variable-line public transport is established with the static passengers reserved in advance as the service object,and the corresponding genetic algorithm is designed to solve the problem,A reference is given to select the appropriate operating parameters.Then,according to the characteristics that the variable route bus will generate new reservation passenger demand in real time during the operation process,a dynamic route optimization model of the variable route bus is established,which considers the influence of the dynamic passengers of the real-time reservation of the bus service on the travel time of the static passengers reserved in advance.,and designed the "dynamic optimization design of bus driving route" for the model,and then carried out the algorithm of "rejecting passengers to reinsert the route for the first time" to solve it.Finally,the feasibility of the method of updating the traffic information at key points and dynamically adjusting the subsequent driving route of the variable route bus is verified by a numerical example.Differences in passenger rejection rates and the impact of dynamic passengers on the travel time of static passengers.The simulation results show that the dynamic optimization of the vehicle travel path in the variable route bus system considering the influence of traffic conditions can improve the attractiveness of the bus and reduce the cost of bus operation.