A Study On Distribution Of Bus Arrival Time And Reliability Of Bus Operation

Buses easily crowd together at stops by fluctuation of bus travel time in transit and the bus parking demand exceeds stop capacity. Coordinating the ability of bus stop and demanding for bus stop, passengers getting on or off and transfer needs, is an important method to improve the efficiency of urban transport system. However, there is short of a set of complete theoretical methods to analyze this phenomenon quantitative, so it is difficult to judge the matching degree between bus stops demand and site parking capacity, as well as bus lines operating reliability level, and also difficult to answer how many bus lines still surplus can be increased at the bus station and other questions.In this article, internal information such as the bus lines, the departure interval at the start stop, parking site location, berth number and so on is collected firstly; the bus external operating environment is analyzed, for example, the expectation and variance of the travel time on road section and the dwelling time at stop; by defining the possibility of multiple buses encountering at a bus stop in arbitrary time interval and exploring its calculating formula, the city bus service reliability is studied on criterion of a-reliability.Secondly, by defining a special summing operation, the process that a bus is blocked to access the next road segment by red phase in front of intersection is described mathematically. The probability density function of the bus arriving time at any stop is derived based on bus travel time distribution on road section, traffic signal phase data and bus stop time distribution at stop.Finally, the influence mechanism of the intersection traffic lights and road travel time fluctuations (changes in the external environment) on bus operational reliability is revealed by the definition and calculation of punctuality index based on routes (PIR) and deviation index based on stop (DIS).In this paper, a new analytical tool for ability optimization and adjustment of bus stop, impact analysis of new projects on the bus parking station (stop) system, designing and evaluation of public transportation system and so on. The basic theory application of public transportation system planning is further improved.