Train operations
Enhancing the safety of train operations to reduce train accident risks
Rail continues to be one of the safest ways to travel, but precursors to train accidents, such as signals passed at danger (SPADs) and train speeding incidents, continue to occur.
Sixteen potentially high-risk train accidents were recorded in 2023/24. This is two more than last year. Six were derailments, including the incidents at Grange-over-Sands and Thetford, which RAIB are investigating. There were also six collisions with road vehicles at level crossings, the most for more than five years.
The number of SPADs by all train types has also been rising over the past three years (see figure 2). And while the SPAD risk metric also increased significantly over 2023/24, this was driven by a relatively low number of SPADs that reached the conflict point.
Concerns continue around the high rate of empty coaching stock (ECS) SPADs. These have a higher number of SPADs per train mile than passenger or freight trains. ECS services account for around 4% of trains, but 18% of SPADs over the past 20 years. This prompted RSSB to undertake analysis into ECS SPADs. This found that 70% of ECS SPADs—where the cause was known—were due to slip-lapse human performance factors. Distracted or not paying attention was the highest sub-category within the ECS SPAD population. This is likely to reflect that ECS drivers often have irregular stopping patterns and encounter more red signals than passenger services.
RSSB have improved the SPAD self-evaluation tool, which has now been upgraded to an online product. It helps users understand how their SPAD management is performing and where improvements can be made. To help reduce and prevent SPADs, RSSB have also developed a guidance document showing users how to complete the SPAD Alert notice and the SPAD Initial Learning notice, with downloadable templates.
RSSB’s data hubs, covering multi-SPAD signals1 and SPADs per million train miles, allow users to dive into more detail about SPAD trends and find out more about some of the signals most commonly passed at danger.
Overspeeding also continues to be an area of concern. An overspeed at Spital Junction near Peterborough, which RAIB is investigating, highlights the risk. The incident led to the train lurching sideways, resulting in minor injuries to some passenger as they were thrown from their seats. A similar incident at the same junction in 2022 was also investigated by RAIB, which found that while the train did not derail it is likely that some of the wheels lifted off the rails.
There has been an increase in reported speeding events over the past three years (see figure 3). There is likely to be significant underreporting of events in this area. This is because the automatic systems that can detect overspeeding do not cover the whole network. Events can go unnoticed if there is not an on-train data recorder (OTDR) assessment, TPWS trip or lineside assessment of the speed.
Speeding is highlighted as an area of action in the RHSS. Developing an industry speed risk data strategy and a risk ranking tool will ensure that our understanding and management of speeding aligns with other operational risks. And Rail Industry Standard (RIS) on managing speed restrictions is also being drafted. It will improve the consistency in how speed restrictions are imposed and monitored.
Ultimately, the risk from SPADs and speeding will be mitigated by the introduction of European Train Control System (ETCS). But, in the interim, the management of these risks remains critical. When published, a refreshed Train Protection Strategy will outline the approach for interim controls to remain effective for use on the mainline railway until ETCS has been widely implemented.
1Signals with two or more SPADs over the last five years.
CIRAS data shows that this year there was an increase in reports discussing risks which could increase the likelihood of a train accident. In 2023/24, CIRAS received 50 reports of this type, compared to 37 last year, and 38 in 2021/22.
This year CIRAS saw a cluster of reports about OFF indicators, highlighting concerns about the risk from trains passing a signal at danger.
Another cluster of reports were about faulty Automatic Warning System magnets. Although these faults were classified as right-side failures, the reports discussed concerns about drivers becoming accustomed to in-cab warnings that were not alerting drivers to any danger ahead. In some reports, the faults had been ongoing for several months.
