公車路線適應式號誌時制模式之模擬

Abstract

都會地區由於現有捷運路權無法全面涵蓋旅次需求以及其他運具服務特性、高費率與停車等問題的限制，公車運輸有其無可取代的地位。實質上，公車運輸除了路網配置、服務與轉運機制的完整性外，尚須提昇營運路線的運輸效率，目前公車運輸效率大多透過即時班車調度與公車專用道等周邊設施來提升，即時班車調度於緊急調派時，大多須策略性脫班與過站不停等措施，公車專用道則成本高且地幅限制多，因此，號誌化路線控制會是較佳的方式，在APTS的環境下，號誌時制設計甚至應具備控制公車準點的功能，而非只強調優先；過去的文獻較少將公車優先號誌運用到控制路線準點的機能上，且號誌系統大多以觸動式為主，操作彈性較低且容易降低幹線車流的續進效率，甚至增加延誤時間，因此，建立一套兼顧應用彈性、設施成本與準點效果的號誌系統有其必要。 本研究對路口號誌時制設計的考量，係以號誌路網車流中的小客車與公車運行管制為基礎，由公車優先方式與適應式號誌策略等文獻的啟發之來建立系統架構，發展控制邏輯來構建模組模式，並由模擬結果進行分析，以掌握各種控制策略的績效與特性。本研究透過普松分配與隨機公車班距，於路線起點產生小客車與公車流動，由車隊擴散關係進行小客車流的路段移動，採用階層化觀念架構，將號誌控制分為路口控制階層與路線控制階層，前者具有執行與回復路口定時式號誌控制時制的機能，後者則具有適應式公車路線號誌時制調整的機能，最後透過班表控制或班距控制邏輯以彈性決定路口的控制型態；系統輸出績效則包括路口號誌控制績效與公車站位績效。 本研究模擬作業以一測試路網為例，依據控制邏輯與補償時相，界定五種測試方案，經由一系列模擬與分析來確認模式有效性，比較與歸納不同控制方案下的運行效果。

It has been found that MRT right-of-way can not be widely spread out to fulfill all possible demand in modern metropolitan area. Also, due to some key problems, such as restrictive services, high rate of fee, low mobility during rush, and the parking space limitation for most of other modes, urban bus transit is getting more preferable to public users. In addition to a satisfactory the network layout, service frequency, and transferring system, bus transit may be required to enhance the operating efficiency along routes. This can be done mostly via the use of real time dispatching as well as bus exclusive ways. the former applies usually a timely stop-skipping treatment for emergent needs, the latter are greatly limited by roadway layout and usable space, and may even incur high setting cost. Therefore, an on-route signal control would be a better way to alleviate travel delay and upgrade level of service for roadway users during peaks. However, with APTS environment, such efficiency may not focus on preemption only. Instead, the adaptive signal system should be functioning with higher schedule adhesion capability. Unfortunately, very few of past research had worked on such an issue. Thus, it is necessary to develop a signal control model considering its practical flexibility, system cost, and control effectiveness. This study is intended to develop a signal control model that is capable of evaluating some preset objective functions for efficiently controlling auto and bus movements on the existing transit network. A great deal of studies on bus priority control and signal timing design have been reviewed to inspire the signal system architecture and control logic. The model applies the Poisson distribution to generate auto and bus calls. Auto movements are propagated along each route using the platoon dispersion concept. The entire signal control structure is classified into two, i.e., local control level and route control level. With a pre-timed signal control basis, the former may perform any preset settings and switch back to the preset one as any of the adjusted timing for bus calls was done. The latter is designed for quickly adjusting control timing in response to any bus arrival calls. Finally, a schedule-based logic and a headway-based logic are separately associated with the adaptive signal control structure for optimizing intersection output performance. The system output performance mainly includes intersection control performance as well as bus stop performance. This study defined five test scenarios based on the timing control and phase compensation logic. With a simplified bus network, a series of simulation runs were conducted to verify the model efficiency and validity. The results from various scenarios were also compared and analyzed to reach some valuable conclusions.