Slow down! Detecting overspeeding in blanket speed restrictions

When weather conditions are both extreme and widespread, the speed limit across large routes or areas of railway may be lowered temporarily. This is called a blanket speed restriction and is an important safeguarding measure used in the rail industry in the UK to reduce overspeed risk and maintain the safety of train services.

When are blanket speed restrictions applied?

Extreme weather increases the risk of derailment, collisions, and damage to rail infrastructure. When exposed to high temperatures, track can buckle, making it unsafe for trains to pass over, while gale-force winds can blow trees onto the railway. 

A blanket speed restriction (or a BSR) lowers the speed limit in these conditions, giving drivers more time to react to hazards, and reducing the stress on physical railway infrastructure. But an industry-wide reliance on traditional monitoring and communication methods mean speed restrictions are sometimes missed, resulting in trains travelling much too fast in dangerous conditions. 

‘Old school’ communication makes overspeeding more likely 

Traditional ways of working and communicating have been recognised as an issue in the UK rail industry for years – particularly during blank speed restrictions. And despite the roll-out of GSM-R finishing more than a decade ago, the problem remains apparent. 

In fact, the Rail Accident Investigation Branch (RAIB) found that poor communication was the root cause of overspeeding incidents during BSRs, leading to drivers and signallers completely oblivious to any blanket speed restriction. 

Overspeeding increases the risk of derailment or collisions in normal conditions, and even more so in extreme weather, so it’s not something that should be taken lightly. 

Too easy for information to be missed 

Even though digital tools are available, train drivers and control teams still tend to find out about blanket speed restrictions via notice boards, pre-shift briefings, or over the phone. And because BSRs don’t use physical signage alongside the track, the control room ends up bearing the responsibility of communicating restrictions (and monitoring them).

The issue is, the technology needed to do this effectively is largely absent from rail control rooms across the UK. And until recently, there’s been no means of monitoring whether blank speed restrictions are being followed – which also means no one really knows if the risks of derailment and collision are actually being mitigated.

The lack of modern systems places an additional workload on frontline teams – often when extreme weather has already created disruption – and can result in vital safety information being lost in the ether.

Passengers and staff are being put at risk because the message simply isn’t reaching the driver. Speeding incidents are being investigated after the event or missed entirely, instead of being identified and addressed at the time. 

What can be done to mitigate overspeed risk? 

To maintain safe services amidst a blanket speed restriction (BSR), temporary speed restriction (TSR), or emergency speed restriction (ESR), control rooms need to understand what’s happening across all of the services that are running in real time.

Without an always up-to-date understanding of services or a defined alerting process, it’s easy for important safety information or speeding incidents to be missed. 

Using automation to stop speeding incidents in real time 

We’ve developed a new Overspeeding module within Sirocco – our real-time monitoring and operations tool that gives control teams a live, consolidated view of all services and service data.

Information surrounding blanket speed restrictions is captured by Sirocco and brought into view for the control team when restrictions are applied.

If a train service goes beyond the speed limit, the control team is alerted in real time, so the driver can be contacted. As this is automated within Sirocco, speeding can be addressed at the time – instead of investigated after the fact – preventing prolonged overspeeding incidents and reducing the risk of derailment.

False alarms are disruptive. Working in partnership with a train operator, we built the Overspeeding module to ensure control teams are only alerted to true cases of overspeeding. For example, alerts are only triggered when a train travels more than 10% about the speed limit, for more than 30 seconds. We’ve also set a limit of just one alert per service, meaning control rooms aren’t being continuously disrupted by the same incident. However, these thresholds can be adjusted as required.

Solving control room challenges 

We don’t sell products, we solve problems. Our solutions are developed by people who genuinely understand and are passionate about the rail industry. If you want to learn more about Sirocco’s full range of features, send us a message. 

You can also learn more about Sirocco here.