台鐵三位式號誌系統安全時距公式之建構與分析

Development and Analysis of Three-aspect Signal Close-in Time Formula for Taiwan Railway Administration

列車於路線運轉的過程中，為避免發生追撞及對撞，先行與續行列車之間必須以號誌分隔，以保持一定的安全間距，因此無論就規劃、設計或營運的角度而言，號誌安全時距皆為軌道運輸相當重要的課題。目前台灣地區的軌道系統大多數採固定區間閉塞號誌系統，故本研究以台鐵的三位式號誌系統為研究對象，深入探討並建構複線運轉過程中，先行與續行列車進站與離站等情境下的號誌安全時距公式。在案例分析中，本研究挑選目前台鐵最常見的推拉式自強號與EMU500通勤電聯車分別作為先行列車與續行列車，配合板橋車站的路線特性進行號誌安全時距公式試算，同時針對各種影響因素進行敏感度分析。從敏感度分析的比較結果發現，閉塞區間長度、列車加減速度，以及巡航速度等，皆是影響號誌安全時距的重要因素。本研究所提出的號誌安全時距公式以及敏感度分析結果，可作為未來國內發展軌道容量分析方法的參考。

In order to avoid crash between successive trains, the following train must follow the indication of the signal system to keep sufficient distance away from the preceding train. In this paper, an analytical model for estimating signal close-in time for the three-aspect signal system of Taiwan Railway Administration (TRA) is developed. This model considers many factors that other researches have never taken into account, including train acceleration (deceleration), cruising speed, train length, signal block length, gradient, number of tracks in station, and dwell time. In the case study, the real parameters of Push-Pull express train, EMU500 commuter train and Pan-chiao station from TRA are selected for the experiment. The sensitivity analysis shows that train acceleration/deceleration rate, cruising speed, and block length are dominating factors of signal close-in time. The results of this study can be further applied to develop a rail capacity model for TRA.