Research On Travel Time Reliability Of Urban Rail Transit Network

In recent years,with the increasing urban population in our country,urban residents pay more attention to their life quality in various aspects such as food,clothing,housing,and transportation.Therefore,the requirements for travel punctuality and convenience become higher and higher.In order to better implement and develop the green travel concept,big cities have accelerated the construction process of urban rail transit,continuously strengthened the concept that makes the urban rail transit as the core transportation of the urban public transportation,and gradually expanded the scale of rail transit networks.Big cities build multimode and diversified urban rail transit infrastructure with subways,monorails,urban express rails,light rails,trams,etc.,to form a multi-standard urban rail transit network for meeting passengers’ travel demand in different areas.There are many studies on the topological characteristics of a single rail transit network.However,few scholars have superimposed different rail transit sub-networks in their research.Therefore,according to the difference in departure interval,passenger capacity,and running time between multi-standard rail transit,this paper combines different rail transit systems to build a urban rail transit network by augmented state-network method.It can better reflect the difference in data such as travel costs and travel time among multi-standard rail transit,and provide model for the travel time reliability calculation in a urban rail transit network.Secondly,most of the current research focus on the travel time reliability in road network,while few studies measure the travel time reliability in rail transit networks.In the travel of passengers in the urban rail transit network,as rail transit vehicles run according to train schedules,so the travel time of passenger is determined.However,the walking,transfer,and waiting time are all random,which greatly affects the reliability of passengers’ travel time,especially in the morning and evening rush hours.Therefore,according to the randomness and ambiguity characteristics of passengers’ travel time in a rail transit,the study integrates cloud theory and three-point estimation method to calculate the travel time reliability in a urban rail transit network.As the pace of urban life accelerates,passengers’ perception of the value of travel time reliability is much higher than the value of travel time.Therefore,passengers pay more and more attention to the travel time reliability of the route when making travel decisions.However,few studies regard travel time reliability as a constraint for effective route selection.The study puts forward the reliability of travel time as one of constraint when determining the effective path,and improves the traversal search algorithm of the graph.Then the generalized cost of each effective route is computed,which helps passengers choose a travel route with higher travel time reliability and lower cost.Research on the travel time reliability of the urban rail transit network is not only an important subject to ensure passengers’ travel reliability and improve passenger’s service quality,but also a necessary work to promote the healthy and sustainable development of our country’s rail transit.