Reliability – Community of Metros Benchmarking Group

Research: Performance of New Fleets

October 11, 2025June 20, 2025

Rolling stock performance typically follows a ‘bathtub curve’ throughout a vehicle’s ~40-year lifecycle. This is characterised by higher rates of failures in the early stages due to design or assembly defects or staff unfamiliar with the equipment, which falls to a lower, relatively stable rate of failures during the normal operating period. We would then expect failure rates to increase again towards mid-life or end of life.

The study analyses rolling stock failure rates of individual vehicles within a metro fleet relative to their time in service, allowing members to compare the bathtub curve for new fleet failures across metros and within fleets.

Factors impacting failure rates of new fleets

Research: Metro Reliability

October 11, 2025February 26, 2025

Metro reliability is a crucial element of metro operations and customer service. During the core COVID-19 period, metros’ attention seemed to shift away from reliability to more pressing needs at that time, however it is clear that reliability has returned to one of metros’ top priorities as ridership returns.

The research collected the line-level data from 23 metros for 182 lines. It reviews how metros measure reliability and set reliability-related targets. It also investigates reliability performance based on both the network- and line-level data, and explores the successful initiatives that have been implemented by metros for reliability improvement.

Research: Reliability of Signalling Equipment

March 16, 2021April 15, 2020

Signalling is a safety- and service-critical metro asset. Across CoMET and Nova metros, signalling is the second-highest cause of delay incidents, and cause approximately half of all delay incidents for very reliable metros. This study analysed information from 26 metros about their signalling equipment, looking in detail at six sub-assets: point machines, interlockings, track circuits, axle counters, train stops, and signal heads. The study compares these sub-assets, including their age, reliability, and inspection/maintenance regimes, and collects initiatives that metros are pursuing to improve signalling reliability.

Metros with older and more traditional signalling systems tend to have more trackside signalling equipment, which may lead to more potential for failure and greater need for maintenance interventions to maintain reliability. To improve signalling reliability metros are rationalising their asset bases, as well as pursuing both solutions that can be retrofitted into their existing systems and new systems such as CBTC.