Research On The Identification And Optimization Method Of Bus Bay Stop Risk Area Based On Conflict Time And Space Distribution

With the advancement of urbanization in China,urban traffic pressure is gradually rising,making the development of public transportation more critical in the process of urban development.As an important part of public transportation,conventional urban buses,with its level of service and safety,affects the quality of life of urban residents and is also an important part of urban construction and development.In the process of entering and exiting the bus stop,bus vehicles have the compulsory behavior of changing lanes,which is very likely to intertwine with the surrounding vehicles,causing chaotic traffic flow and traffic conflicts around the bus stop,thus generating potential traffic accident risks.Therefore,this paper investigates the identification and optimization methods of risk areas of bus bay stops based on the spatial and temporal distribution characteristics of traffic conflicts,with the aim of improving the design alignment,signage and traffic flow status of bus bay stops,improving the operational safety level of bus stops,and providing some theoretical support for the optimization of relevant specifications.Firstly,this paper systematically summarizes the theoretical basis of traffic conflicts,analyzes the mechanism of traffic conflicts in the functional area of bus bay stops,and classifies the types of traffic conflicts in bus bay stops.Considering the characteristics of bus bay stops,a scientific designed traffic conflict survey scheme for port and bay stops has been developed.The survey data are pre-processed with the help of the software Tracker.Secondly,based on the survey data of five sample stations in Guangzhou,the speed characteristics and vehicle lane change characteristics of the bus bay stops are analyzed,and the severity threshold classification criteria and spatial distribution characteristics of various traffic conflicts are discussed.With the help of VISSIM simulation platform,multiple groups of simulation experiments are set up using the control variable method,and the relationship between traffic conflicts and traffic flow parameters such as traffic volume,speed and the number of incoming buses is quantified based on the simulation results.Then,based on the traffic conflict theory,a grey clustering method is used to construct a model for calculating the overall safety level of the functional area of the bus bay stops,with the number of conflicts,the proportion of serious conflicts,the conflict rate and the conflict density as evaluation indexes.At the same time,based on the results of the rasterization,an internal safety level calculation model of the functional area of bus bay stops is constructed by integrating the traffic conflict characteristics of each raster.Thus,macroscopic and microscopic calculations of the safety level of the bus bay stops are achieved.Finally,based on the analysis of traffic flow characteristics and the construction of a safety level calculation model for port and bay terminals,a method for optimizing the safety level of port and bay terminals is proposed.By processing the trajectory data of bus vehicles entering and exiting the bus bay stops,a trajectory model of bus vehicles entering and exiting the bus bay stops is constructed by polynomial fitting.And based on the proposed trajectory model,an optimization method of the design parameters of the bus bay stops is then proposed based on the trajectory model.At the same time,for the problem of chaotic traffic flow in the functional area of the bus bay stops,management measures such as bus vehicle lane change warning signs,no-lane-change markings and speed control are proposed.Simulation results show that these measures can effectively reduce the traffic conflicts at the bus bay stops.The result of this research can provide a certain theoretical basis for improving the quality of urban bus services and constructing a more humanized traffic system.