Institute of Transportation, MOTC

　　Realizing the effects of the price difference between cars and high speed rail on drivers’ modal choice behavior is a crucial issue for making intercity travel decisions. Differing from previous studies, in which discrete choice models were used to discuss drivers’ modal choice behavior, this paper attempts to apply the cusp catastrophe model to discuss drivers’ modal choice behavior under various modal price scenarios and describe their non-linear characteristics through quantitative and qualitative analysis. According to the empirical study, the questionnaire survey that was conducted received 614 valid samples from freeway drivers who travel long-distance in Taiwan. The proposed behavioral model used “modal choice intention” as the state variable while “switching barrier” and “modal price difference” were used as the splitting factor and normal factor of the control variable, respectively. 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 behavior especially while encountering higher oil prices (NT$34/litre) with 60% discounts implemented for HSR tickets.