Study On The Optimization Of Public Transit Network

The speeding urbanization in our country leads in the rapid growth of car ownership,while the traffic infrastructure construction is lagging behind, which results in the urbantraffic congestion and the prominent contradiction between urban residents travel demand andpublic transportation development. Based on existing urban road system and the public transitnetwork, giving public transport development the priority and optimizing urban public transitnetwork, the public transit service level will be greatly improved and the resident travelconsumption shortened, fundamentally easing traffic congestion.First of all, this paper introduces the basic content and optimization principle, anddiscusses the evaluation index from aspects of a single bus line and the overall public transitnetwork;it briefly introduces the traffic planning software TransCAD,and researches on threecategories of database: city road network, traffic zone and public transit route system; Secondly, this article elaborates the traffic demand forecasting method as well as the basicprinciple and it explains the stages of transportation planning model in detail, comparing themain characteristics of each model; Finally, taking Lanzhou city as an example, we set up twocategories of database: Lanzhou city road network and traffic analysis zone, inputting a largeamount of basic data. Then the public traffic demand in Lanzhou is forecasted usingreasonable traffic planning model which is selected with the consideration of realities.Lanzhou city bus lines system is established on the basis of the database, which providestheoretical support for the optimization of public transit network. We make specific analysisof the public transport system and the main problems in present situation of Lanzhou cityfrom three aspects: bus operation, public transit network and public transport facilities. Wescreen and select the bus routes to be adjusted according to six evaluation indexes: linelength,headway, line overlap factor,line nonlinear factor,section non-equilibrium factor ofpassenger flow and stop non-equilibrium factor of passenger flow; we put forward reasonableadjustment scheme to each line respectively according to its characteristics; Finally, weevaluate the optimization scheme with the evaluation index.The article takes the recent construction situation of Rail Transit Line1in Lanzhou intoaccount, giving adjustment to some of the main congestion nodes of bus lines, thus toimprove the rationality and manipulability of the scheme.