Research On Vehicle Routing Plannning Of Flex-route Transit

With the rapid growth of urban population and the number of private cars,problems such as urban traffic congestion and environmental pollution are increasingly serious.The country vigorously promotes the priority strategy of public transportation,and guides urban traffic to the direction of green sustainability.However,the development of public transport has fallen into a dilemma that traditional transit is not only expensive but also inflexible.So that it is urgent to explore new mode of public transport to break the predicament.Flex-route transit service,which contains fixed stations on a predetermined schedule and flexible routes providing on-demand service,is thought as an innovative public transportation and a promising option in low-demand areas.This paper mainly studies the vehicle routing problem of the flex-rout transit service.(1)This paper analyzes the key parameters,passenger characteristics and operation rules of the flex-rout transit service,sums up the advantages and disadvantages of this service.Combined with China's national conditions,this paper also expounds the necessity of developing flex-rout transit service.(2)Considering giving precedence to the special passengers and aiming to minimize the operating costs and passenger costs,this paper proposes a model of vehicle routing problem of flex-rout transit service.The vehicle routing problem is split into two sub-problems: passenger allocation and route planning.A genetic algorithm is designed to solve the passenger allocation problem and an insertion algorithm is designed to solve the route planning problem in the process of designing the algorithm.At the same time,these two algorithms are coupled together.(3)This paper proposes two optimization strategies,station attraction and path replanning,to reduce the service rejection rate in of the flex-route transit.Station attraction strategy offers location information to rejected passenger,which is a remedial strategy.Path replanning strategy merges the required station together ahead of time.The simulation results show that the station attraction strategy optimization effect is better in middle and low demand density,while in the middle and high demand density,the path replanning strategy optimization effect is better.In this paper,by studying the vehicle routing problem of flex-rout transit service,a mixed solution algorithm is designed,and two optimization strategies are proposed,which promote the theoretical research of the flex-rout transit service.