Efficiency Analysis And Management Of Passengers Flow On Metro Platform

As an important transportation mode,metro system is playing an increasingly important role in urban congestion mitigation. Thus the daily ridership of metro lines usually reach or even exceed the designed passenger capacities shortly after metro line opening, especially in densely populated large cities. As a consequence, metro stations are often crowded with boarding and alighting passengers, resulting in inconvenience, delays, and at times danger during peak hours. In order to avoid pedestrian crowding, improve passenger boarding and alighting efficiency would help decreasing pedestrian density in metro station. Thus in the present paper, we explore factors affecting passengers'efficiency on metro platform by surveying and simulation, aiming to provide basic parameters for subway management and passenger flow organization.An experiment concerning passengers' movement characteristics was designed and performed to study the maximum speed of free walking. Then, a field survey was organized in Chengdu to investigate boarding and alighting characteristics on metro platform. Based on the results of experiment and observation, a passenger flow simulation model was formulized and validated. Effects of factors including waiting passenger number and distribution, stair and escalator combination form, and time interval between successively arrived trains was detailed based on extensive simulations. Results indicated the following truths:1) Although the influence of different waiting pattern on boarding and alighting efficiency was not significant, it was found that boarding passengers wait on one side of the train door could provide higher efficiency and thus was the recommended queuing mode. Besides, when alighting passengers have the priority, the overall efficiency is higher than when boarding passengers have the priority. Moreover, it was found that the facilities layout could result in different vertical transit facility usage, and as a consequence extra delay.2) The simulation of passenger flow on metro platform indicates that with the increase of waiting people on the platform, the passenger alighting time became longer. When there were 2000 people waiting on the platform, the last passenger's dwelling time is 107.26s, which is 65%longer than the time when no one was waiting on the platform. The shortest passenger's dwelling time is affected by the number of waiting people on the platform, the largest value when there were 2000 passenger waiting is 4.68s longer than the one when there was no passenger waiting on the platform.3) Simulation results indicate that stair-escalator combination form influences platform flow performance. When we put a descending escalator in between a stair and an ascending escalator, the pedestrian flow efficiency is the highest. Thus, it is suggested that this combination form should be used in the stage of planning the metro station. Furthermore,passengers on metro platform should be advised to go out by stairs instead of escalators,which will benefit the efficiency of passengers.4) The effect of time interval between two successively arrived trains at the opposite sides of the same platform on pedestrian dwelling time indicates there is a threshold value of the time interval. For train interval less than this value, conflicts among passengers from different trains can be observed, which prolonged the passengers dwelling time as well as shrinks the difference of different stair-escalator forms.