| Summary: | 碩士 === 國立交通大學 === 運輸科技與管理學系 === 93 === 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.
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