捷運系統營運穩定度與效率評估模式

Abstract

捷運系統的建設發展在改善都市機能與交通動線上扮演著重要的角色，面臨都市人口的迅速成長，為能有效紓解尖峰時段的擁擠人潮並且滿足運輸需求，捷運系統營運效率與穩定度同時受到營運業者與使用者的重視。為提供快速、可靠、便捷的運輸服務，班距的設計與安排實為營運的最高準則，優良的設計必須兼顧系統服務穩定度與效率，有效且穩定的運用軌道資源。然而，過去的研究多著重於穩定度的分析而輕忽效率，如此可能導致捷運系統服務效益不彰，而尖峰時段過度使用的服務模式亦將導致穩定度的大幅下降。因此，本研究從容量分析的角度，以「期望回復時間」作為評估指標，研發建構能夠兼具「穩定度」與「效率」的流程評估模式，對「穩定度」與「效率」之間所存在的權衡關係進行深入探討，以提供系統營運業者更全面的資訊，讓營運單位在提升營運穩定度的同時，確保不會造成資源的浪費。

A successful metro operation is a balance mix of operational stability and efficiency. Due to the potential system disruptions, metro operation should incorporate an appropriate level of slack in order to efficiently recover the system to normal state. Insufficient slacks results in unacceptable operational stability while surplus slacks incur unnecessary expense and waste. Consequently, there exists a trade-off relationship between operational stability and efficiency, of which the evaluation is an extremely important topic for metro operation. In this study, an analytical model is developed based on capacity analysis concept to assess the stability and efficiency of metro operation by “expected recovery time” and “capacity utilization” respectively. The point estimate method (PEM) is also introduced to quantify the uncertainty of operational stability arising from the randomness of system disruptions. Empirical results show that the developed tool not only can evaluate the operational stability and efficiency of the metro system but also identify critical sections and time slots the operators should look into with the associated uncertainty. This evaluation process provides metro operators with a quick look on their operational strategies regarding stability and efficiency, helps them provide reliable and robust services to their customers, and return on shareholder’s investment.