Research On Bus Bunching Problems Under Bus Priority Environment

Based on the discrete event system,this paper uses the time-driven method to push on the simulation clock,simulates several influencing factors that affect bus bunching,and analyzes the results obtained in order to summarize the primary cause of the bus bunching phenomenon.In order to improve and alleviate bus operation problems,improve bus operation efficiency,and increase the reliability and stability of bus operation,it has certain practical significance.First of all,according to the investigation,the factors that affect the bunching problems are analyzed.The digital simulation method of discrete event system is selected.Combined with the time-driven method of discrete event system simulation clock advancement,the simulation methods at three different levels of macro-level,meso-level,and micro-level are summarized,and the program simulation and influencing factors of bus bunching at the meso traffic simulation level are selected.Use Matlab software to simulate the three factors that may cause the bus bunching,such as the departure frequency,signal delay and driving habits.By controlling the other two variables,perform single-variable simulation experiments on these three factors respectively.The time-space images corresponding to the influencing factors and the time-distance images between adjacent departure buses.Comparing the analysis results presented in the figure,we can further obtain the impact of these three factors on varying degrees of causing the phenomenon of bus bunching.Then suppose that in the bus lane,due to the small interference of other vehicles and the signal control of the bus lane at the signal intersection,the influencing factors other than the departure frequency and driver habits are excluded.Thus,the frequency of departure and the habits of the driver can be re-analyzed.It can be seen from the results that the headway between the bus shifts and the shifts on the bus lanes becomes more uniform than before,its running trajectory also becomes more stable,and the bus operation efficiency is significantly improved.However,changing these two factors that affect the cross-training will still cause a significant increase in the cross-training phenomenon.Finally,the study found that the waiting time of passengers at the station was prolonged due to the cause of bus bunching,so the waiting queue for passengers at the station will be longer,so that the bus witch arrives later than the scheduled time will be further delayed by the station.According to the actual situation,it can be found that the attraction of the passengers who just got on the bus at the nearest stations is much lower than the impact of the passengers at the further stations,plus the time difference of the OD attraction of different passengers during the morning,middle and evening peak hours.It will cause the occurrence and attraction of passengers at some stations to increase sharply,causing station passengers to accumulate,causing delays to vehicles and causing bus bunching problems.