Journal of Korean Society of TransportationISSN:1229-1366(Print) 2234-4217(Online)대한교통학회

During the process of transportation demand forecasting for future, a network calibration is performed to represent well the pattern of the route choice in the base year. In this process, it is necessary to accurately reflect relative magnitude of the path costs in the route choice behavior model, which the travelers actually perceived. KTDB data distributed by Korea Transportation Institute (KOTI) uses BPR function as highway performance function. The BPR function representing the link cost recognized by travelers consists of free flow speed, capacity and toll. This study explained possibility of distortion in the results of transportation network analysis due to errors in flow and speed relationship function if parameters 𝛼 and 𝛽 in the BPR function was arbitrarily adjusted during the network calibration including toll roads by using KTDB data. Therefore, the study tried to reduce the errors by introducing the concept of differentiated weight within the link performance function to reflect different preference in route choice behavior by highway functional hierarchy. The influence of toll on route choice have been analyzed by using the value of time (VOT) based on the average wage until the present days in South Korea. Therefore, in this study, validation analysis was performed with the observation data of web-navigation whether the wage-based-VOT adequately expresses the level of impedance in the transportation network analysis. The study showed that the VOT, which is actually perceived by the travelers in choosing path, is larger than the VOT presently used in network analysis in the South Korea. In other words, this study explained the necessity of 𝜆^type(0<𝜆^type≤1) as the differentiated weight of the toll, because this study found that the effect of toll on the route choice is actually less than that of the previous analysis.