運輸走廊瓶頸路段擁擠收費與捷運補貼之研究

Pricing Congestion Highway and Subsidizing Rail Transit in a Single Bottleneck Corridor

本研究考量運輸走廊兩替代運具一小汽車、捷運，利用最適控制理論建構一動態運具指派模式，發展演算法求算每個時間點上對應兩運具使用人數變化情形；於一階必要條件乘數分析可推導小汽車之動態擁擠費，並擬以擁擠費收入用淤補貼捷運營運成本，藉此增加發車班次數、縮短時間延滯、吸引捷運旅次，舒緩瓶頸路段擁擠，進一步並由演算法重新求解兩運具使用人數變化。此外，本研究之結果可求算一最適補貼額使系統均衡成本達致最小，另亦可依即時之擁擠狀況，調整瓶頸路段紓解率，釋出可用紓解量。故可提供交通管理單位研擬動態擁擠費、補貼策略及最適補貼額或適時調整瓶頸路段紓解容量之參考，藉此讓兩運具使用率達到最適配置狀態。 This study examined two substitute modes-car and transit in a single corridor, and applied the Optimal Control Theory to formulate a dynamic traffic assignment model. An iterative algorithm was proposed to solve this Optimal Control Problem which showed the two-mode assignment evolutions at each time interval of the study period. From the first-order necessary condition analysis, an optimal time-varying toll could be derived and obtained. The study further proposed a strategy in which transportation authority collected the toll revenue from car users to subsidize rail transit operating cost to increase the frequency of transit dispatching runs and shift car trips to transit trips. As a result, an optimal subsidy, which minimizes system equilibrium cost, could be determined. Finally, transportation authority could also release a latent capacity which is considered to be reserved for the adaptive management of high-level congestion.

This study examined two substitute modes-car and transit in a single corridor, and applied the Optimal Control Theory to formulate a dynamic traffic assignment model. An iterative algorithm was proposed to solve this Optimal Control Problem which showed the two-mode assignment evolutions at each time interval of the study period. From the first-order necessary condition analysis, an optimal time-varying toll could be derived and obtained. The study further proposed a strategy in which transportation authority collected the toll revenue from car users to subsidize rail transit operating cost to increase the frequency of transit dispatching runs and shift car trips to transit trips. As a result, an optimal subsidy, which minimizes system equilibrium cost, could be determined. Finally, transportation authority could also release a latent capacity which is considered to be reserved for the adaptive management of high-level congestion.