以劇變模型分析高速公路實施擁擠收費之駕駛人路線移轉行為

A CATASTROPHE MODEL FOR ANALYZING DRIVER ROUTE SWITCHING BEHAVIOR DUE TO CONGESTION CHARGING ON FREEWAYS

未來高速公路全面實施電子計程收費後，在收費技術可行的前提下，為有效落實擁擠管理，可配合推動擁擠收費政策。不同於過去研究採個體選擇模式，本研究應用尖點劇變模型，探究小汽車駕駛人在假設性擁擠通行費率情境下之路線移轉行為，並了解其可能存在的非線性特徵。實證研究針對臺灣西部高速公路小汽車駕駛人進行問卷調查，共蒐集1,121份有效樣本。透過定量與定性分析方法，選定路線移轉行為作為狀態變數，單位通行費率與移轉障礙則分別為控制變數中之正則因子與分裂因子，校估出四種擁擠情境下之路線移轉行為模型，並檢定控制空間中六個區域的樣本結構分布比例的差異性，進一步解釋駕駛人路線移轉行為產生之發散性、突變性、滯後性與雙重性等劇變特徵。當駕駛人認知的移轉障礙較高，且在擁擠通行費率每公里訂為1.2及1.5元時，路線移轉行為最易發生不連續變化現象。

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.