Research On The Stimulation And Application Of Bus Operation Model With Capacity Constraint And Passenger Heterogeneity

The stability of public transport operation is an important indicator of the reliability of bus systems.Nevertheless,the complex bus operation environment leads to instability in public transport operations.In order to clarify the impact of different simulation environments on bus operations in public transportation system,the first main research component of this paper is to investigate bus systems with capacity constraints,and bus systems accepting seniors,respectively.Firstly,as the capacity constraint has a crucial impact on the operation of bus systems,this paper introduced capacity constraint based on the bus trajectory model.In this paper,the bus dwell time was calculated by considering the passenger boarding and alighting time,as well as two scenarios: the bus with no capacity constraint and the bus with capacity constraint,respectively.Based on these factors,a stimulation algorithm was designed.With the simulation algorithm,this paper analyzed the relationship between the capacity and passengers’ waiting time,taking passenger arrival rates and the capacity as variables in the simulation.The results indicated that the total passenger waiting time would decrease firstly and then increase with the increase of the capacity constraint of the vehicle,and once the capacity of the vehicle exceeds a certain threshold,the total passenger waiting time would level off.Besides,the further analysis showed a positive relationship between this threshold and the passenger arrival rate,which was then fitted as a quadratic function.It is found that there is an optimal capacity that results in the lowest passenger waiting time.Additionally,this paper compared the case without and with capacity constraints and found that the introduction of capacity constraints has the effect of balancing the headway and avoiding the occurrence of bus bunching to a certain extent.The research results would enrich the basic theory of bus systems and provide a theoretical basis for scientific planning and management of bus systems.Furthermore,as China’s population structure changes,the proportion of seniors is in the tendency of increasing,the impact of senior passengers on the public transport system urgently needs to be studied.While studying the bus system,this paper also introduced the elderly passengers,and then divided the arriving passengers into two categories: senior passengers and ordinary passengers.In this paper,a dual CBD bus line was constructed for simulation with control parameters adopted to control the total demand of the system,the time required for senior passengers to board and alight,and the proportion of the senior passengers in the system,to investigate the operation of the bus system.In addition,this paper evaluated the performance of the system in terms of headway deviation,bus capacity,system operation and bunching phenomenon,by altering the values of the control parameters to make the system operate under different simulation conditions.It was found that the addition of a small number of senior passengers did not have a significant impact on the stability of the system,and the bunching phenomenon within a second CBD would be more severe when the system has a higher proportion of senior passengers.The time required to board and alight at stations with high arrival rates of elderly passengers is the main cause of transit delays.The relatively large proportion of the senior passengers and the longer time it takes for them to board and alight the bus have a considerable impact on the operation of the bus system,so in order to address the problem of delays caused by the senior passengers,the second major research component of this paper was introduced: control measures and the design of seniors bus.In this paper,the control measures of seniors bus were proposed for the public transportation system that accepts seniors.The seniors bus is designed to be a dedicated bus for seniors and is intended for senior citizens only.The senior passengers would take less time to board and alight when travelling on a seniors bus.In this paper,no control measures,the control measures of zonal express,and the control measures of seniors bus were compared in the systems with different proportions of the senior passengers.The study found that the proposed control measures can stabilize the bus running trajectory to a certain extent,and it has preliminary feasibility.In order to address the issues of inadequate comfort for the senior passengers,the slow speed of boarding and alighting,and conflicts between passengers,as well as providing further possibilities for the use of senior bus,this paper presented a detailed analysis and explanation of the problems existing in the current bus design,such as the unreasonable layout of the interior space,the relatively high height of the bus,and the lack of supervision and control of passenger boarding and alighting.The design of the seniors bus is an improvement on the existing bus design,and this paper proposed a design scheme for seniors bus from the aspects of vehicle type,senior citizens’ chairs,partitions,guide panels,body height and interior layout.