Investigation of the Factors Affecting the Reliability of Urban Bus System

To ensure sustainable development in cities, the maximum efficiency in the use of public transportation systems should be provided by using sustainable infrastructure investments providing high capacity, instead of supplying the rapidly rising private vehicle based demand. Urban bus systems which mostly take the maximum share in public transportation and are operated under mixed traffic conditions, are highly affected the road and traffic conditions traveled along with them. In recent years, "Reliability" which is defined as the ability of depending on a schedule or headways and a constant travel time, is often used in assessing the performance of transport systems. In this study, the reliability values of some bus lines selected from ？zmir were calculated and the effect of traffic flow conditions on reliability is investigated. Traffic observations were made on the arterials used by the selected lines and simulations were made by using Aimsun 6.1. As a result, it is determined that the reliability increases when the flow speed and number of lanes increases, and decreases in the case that the number of buses stopping at a certain bus station increase