The Rail Accident Investigation Branch (RAIB) has undertaken a preliminary examination into an incident of overspeeding (excessive speed) at Hitchin in Hertfordshire last December.

The incident occurred at 10:39 on Thursday, 11th December 2025, when the Great Northern 10:12 London Kings Cross to Ely service, train reporting number 1T20, passed over Cambridge Junction onto a diverging line at an excessive speed.

The permissible speed for a train travelling straight ahead on the Down Slow line is 75 mph, but a permanent speed restriction of 25 mph is in place for trains crossing the points over the junction onto the diverging route. CCTV evidence confirms that the signals for the route were displaying the correct indications, and the junction had been set correctly for the train to pass from the Down Slow line onto the diverging route.

However, when the train crossed the points onto the diverging route, it was travelling at 56 mph. The excessive speed caused it to lurch sideways and resulted in several passengers falling out of their seats, fortunately, with no reported injuries; the train also suffered no damage.

As well as undertaking a preliminary examination into the circumstances surrounding this incident, the RAIB has looked at similar incidents on the East Coast Main Line, at Grantham South Junction on 25th February 2025 and 26th September 2025, and at Spital Junction, Peterborough, on 17th April 2022 (report 06/2023) and 4th May 2023 (report 10/2024). The RAIB is still investigating those previous incidents, therefore, as an interim measure, it has published a safety digest for the incident at Hitchin.