Urban Bus Timetable Optimization Based On Slack Time

Nowadays,solving the urban traffic congestion through vigorous development of public transportation has become a consensus in the world.The optimization of bus timetable is very important in the research on bus operation scheduling.At present,the bus timetable in some Chinese cities not only provided departure time from origin stop and arrival time at terminal station,some of them also provided arrival time at important bus stops along the line.However,due to various factors such as traffic flow and road environment during the operation on the actual road,the travel time between stops is full of uncertainties,which directly results in a large deviation of the arrival time of the on line stops,even there has "bus bunching" phenomenon.The timetable loses its original meaning.In order to solve this problem,especially on the basis of the electronic bus stop board development and real-time scheduling,and enhance the punctuality of bus operation under uncertain road conditions,when optimizing the bus timetable,in this thesis slack time was introduced to improve the punctuality of intermediate stations(optimized single operation process time)and optimize the departure interval to optimize the entire bus timetable.Firstly according the property of bus stops,several stops which with high requirements for on-time rate are select as Timing Control Point,and slack time was added into the running time between Timing Control Points,to reduce the influence of bus travel time uncertainty,then build an optimization model with the goal of minimizing the total of expected arrival time deviation at Timing Control Points,optimize the timetable for the single bus operation.Based on the optimal driving time of each section after the slack time is added,it combines theory with practice,take consideration of the total cost of passengers travel time(the time cost of passengers waiting at the station,the time cost of passengers on the vehicle based on the slack time)and company's total operating costs(employee salary costs,bus operating fuel costs,bus depreciation expense),established an optimal departure interval model that meets both best interests,to optimize bus departure intervals in each time period,thus get the optimized entire bus timetable of a line.Then the Monte Carlo simulation method and Genetic Taboo Search Algorithm are used to solve the model.Finally,an example is applied to the model to verify the feasibility and effectiveness of the theoretical model.Introducing the concept of slack time and increasing the punctuality of transit bus at intermediate stations can effectively improve the passenger satisfaction of buses.In this thesis,on the basis of improving the on-time rate of bus intermediate station,taking into account the interests of both the operating company and the passengers to optimize the entire timetable,it is conducive to the full utilization of existing resources to achieve the total system cost operating of companies and passengers.At the same time,the research results can also provide theoretical and practical basis for the implementation of bus information e electronic bus stop board development and real-time scheduling.