輕軌優先號誌最佳偵測器位置之研究

A Study of Optimal Detector Position of Light Rail Transit with Transit Signal Priority

徐喬琦(Qiao-Qi Hsu)

指導教授 ： 許添本

國立臺灣大學/工學院/土木工程學研究所/碩士(2018年)

https://doi.org/10.6342/NTU201802363

摘要

輕軌系統近年來為台灣目前軌道運輸發展重點，民國106年行政院積極推動的前瞻基礎建設計畫中亦包含輕軌系統建設。輕軌系統與傳統鐵路不同，輕軌通過平面交叉路口時與其他運具一樣須依循平面交叉口的號誌行駛，為使輕軌具有較大的優先權通過交叉路口，交叉口通常設有優先號誌控制。目前國內輕軌系統主要採用延長綠燈及縮短紅燈優先號誌策略，在優先號誌控制運作下，輕軌偵測器位置與優先號誌控制的執行有關，藉由輕軌接近交叉路口觸發偵測器，號誌控制器可以計算輕軌抵達交叉口之時間，並決定是否執行優先號誌策略以及執行秒數，適當的偵測器位置可使輕軌停等時間減少、優先號誌績效提升。而國內輕軌系統如淡海輕軌及安坑輕軌系統，輕軌偵測器位置皆採用固定位置，本研究希望探討偵測器位置與交叉路口績效關係，以及影響交叉路口最佳偵測器位置的因素，並歸納出決策交叉路口最佳偵測器位置之準則。本研究透過理論分析法探討輕軌停等時間與偵測器位置之關係以及找到最適當的偵測器位置，並透過VISSIM模擬驗證理論分析法結果。接著進一步探討理論分析法的適用性，透過模擬分析其他影響最佳偵測器位置的因素，最後歸納出交叉路口最佳偵測器位置決策準則。
由理論分析法發現影響輕軌停等時間與偵測器位置關聯之因素包含輕軌行駛速率、延長綠燈優先策略條件、縮短紅燈優先策略執行時間點。偵測器離交叉路口越遠，輕軌平均停等時間越短，但考量輕軌因速率變動因素、設站位置會影響偵測器預估時間與實際抵達時間，造成優先號誌執行效果不佳，因此本研究以輕軌平均停等時間變化轉折點設為最佳偵測器位置。此外，由模擬分析結果發現輕軌班距不影響最佳偵測器位置的決策，但交叉路口交通量會影響，當輕軌方向車流飽和程度高於橫向車流時，適合用理論分析法求得交叉口之最佳偵測器位置；當橫向車流交通量接近飽和時則須考量交叉路口總體延滯，適合用模擬法決策最佳偵測器位置。

關鍵字

輕軌運輸系統 ； 優先號誌 ； 偵測器 ； 模擬 ； 理論分析方法

並列摘要

LRT(Light Rail Transit) has been the critical direction of development in Taiwan. The construction plans of LRT system in many cities were included in the infrastructure plan, which was released by the government last year. In LRT system, in order to let light rail vehicles have a higher priority to pass through the intersection, the intersection is usually provided with priority signal control. The control type is known as TSP (Transit Signal Priority). In Taiwan, two priority strategies - green extension and red truncation are the main control types in LRT system with TSP. The TSP control process is highly related to the detectors. The detector detects an approaching light rail vehicle and sending information of light rail vehicle to signal controller. Then the signal controller calculates the arrival time of light rail vehicle and decides whether to conduct TSP strategies. Therefore, the location of detector would influence the performance of TSP. In Taiwan’s LRT systems, detectors are in fixed position from intersections. This study hopes to discuss the relationship between the position of the detector and the intersection performance, finds out factors that influence the optimal detector position, and explores ways to determine the optimal detector location at an intersection.
In this study, the theoretical analysis method was used to investigate the relationship between the position of the detector and the average stopping time of the light rail vehicle, and to find out the optimal detector position. The result of theoretical analysis was verified by VISSIM simulation experiments. Furthermore, the applicability of the theoretical analysis method was further discussed. Through the simulation analysis of other factors that affect the position of the detector, the method for determining the optimal detector position at the intersection was finally summarized.

並列關鍵字

light rail transit ； transit signal priority ； detector ； traffic simulation ； theoretical analysis

參考文獻

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