Background to RAIB recommendations
102 On 25 March 2019 an incident occurred which prompted an ad-hoc trial of a method of advising drivers by radio of an emergency speed restriction on the route ahead. A 5 mph (8 km/h) emergency speed restriction was imposed at Bushbury Junction, West Midlands, due to a crack in the stock rail of a switch diamond. A watchman was put in place, and in the space of 24 hours, three trains, from different train operating companies, exceeded the emergency speed restriction by a substantial margin. After the second case of overspeeding, Network Rail managers became concerned that any further instances could have serious consequences. After confirming that the emergency speed restriction signage was set up correctly, Network Rail decided that an additional mitigation was required to prevent overspeeding. A recorded message was broadcast to drivers of trains approaching the area over the GSM-R radio system, which is used to communicate between signallers and train drivers. However, a third overspeeding incident then occurred. The driver of this train reported misunderstanding the recorded message, and being confused about the exact location of the emergency speed restriction. The broadcast messages were subsequently suspended. Network Rail is considering the lessons from this incident