Institute of Transportation, MOTC

　　For congestion management purposes, a congestion charging strategy could be implemented to accompany the oncoming implementation of the electronic distance-based charging strategy on freeways. Different from previous studies using discrete choice models to discuss driver route switching behavior, this paper attempted to apply the cusp catastrophe model to discuss driver route switching behavior under various congestion charging scenarios and describe their non-linear characteristics. According to the empirical study, the questionnaire survey was conducted to collect 1,121 valid samples from freeway drivers traveling in western Taiwan. By means of quantitative and qualitative analysis, the proposed behavioral model used “route switching behavior” as the state variable and “switching barrier” and “a unit of charging rate” as control variables. The test of independence was performed to check sample structures for six areas of the control space, and the catastrophe characteristics, such as divergence, catastrophe, hysteresis, and bimodality, of switching behavior were discussed. A higher switching barrier would easily cause discontinuous switching behavior while encountering a unit of charging rates, especially at NT$1.2/km and NT$1.5/km.