軌道電路顯著變數有「號誌設備設置位置」、「曲線半徑」、「坡度」、「存活時間內累積對號列車總班次」、「存活時間內累積非對號列車總班次」,號誌機有「路線形式」、「存活時間內累積對號列車總班次」、「存活時間內累積非對號列車總班次」、「存活時間內平均溫度差」,轉轍器有「路線形式」、「曲線半徑」、「存活時間內累積非對號列車總班次」、「存活時間內平均溫度差」,繼電聯鎖有「路線形式」、「存活時間內累積對號列車總班次」、「存活時間內累積非對號列車總班次」、「存活時間內平均溫度差」。 ;This research is use the data of TRA’s signal system failure report to analyze the signal system of the survival time. Also, use the survival analysis, Cox proportional hazard model that applied in signal system factors, there are three factors included track, train number and weather. Through factors data compilation, model construction, parameter calibration and goodness of fit test for the model, and use the Cox proportional hazard model as a model of relative risk and determine the median survival time, then observe the change in explanatory variables, these can extend the signal system life. As a result, the signal system’s survival time has 75% can survive more than 177 days, 50% can survive more than 449 days and only 25% can survive more than 655 days. Through Cox proportional hazard model, research outcome had reavealed that five significant variables. Also research in track circuit and axle counter, signal, point machine, relay interlocking.