Investigating Operational Efficiency Of Bus Stops With Dynamic Dispatching Control

With the expansion of bus networks and the increase of traffic volume,the congestion near bus stops caused by bus arrivals in bulk and insufficient docking spaces has formed new bottlenecks which deteriorate the level of service of bus transit and traffic condition.Since the passenger demand fluctuates over space and time,it has become a major reason causing bus bunching at different stops over a route.To investigate the inherent bus service and the operational efficiency of bus stops for improving system performance and reliability,the factors causing delay of buses accessing an intended stop are identified,and the berth length of the stop is optimized.To improve operational efficiency,a dynamic bus dispatching model is developed to reduce the sum of users' and operator's costs.The developed model has demonstrate its effectiveness to yield the greater benefit of the users and the operator considering practical constraints,such as the number of buses can be accommodated based on the berth length.Considering the delay subject to the berth length and scheduled bus arrivals that influences the level of bus service,a probability model dealing with stops consisting of multiple berths is also developed.With that the effective utilization rate can be quantified through conducting a comprehensive analysis with calibrated berth utilization,bus arrival rate and the associated service time.Based on the passive block factor,overflow and interlock phenomena caused by shunt delay,confluence delay and queuing are analyzed by using a maximum threshold model in which subject to a safety constraint.Further,the probability of the greatest congestion of a stop may be estimated.Based on the outcomes of the probabilistic model,the capacity under different docking principles can be approximated subject to given inter bus arrival times and the service time of a berth.Thus,the capacity reduction of the external motorway adjancent to the stop under different docking principles can be analyzed.During peak hours with greater passenger flow at stops and heavy traffic on the adjacent streets,a dynamic dispatching model is desirable to reduce congestion and improve bus service.Dispatching buses dynamically subject to demand and traffic conditions may significantly ease the congestion and excess waiting time problem.The dispatching model intends to optimize departure interval with the linear quadratic method so that buses may arrive the stops with relative even headway.The results show that the developed model seems effective in alleviating congestion at the critical bus stops on the study site.