The driver of a local train on the JR Musashino Line temporarily lost consciousness due to sleep apnea syndrome on Monday, resulting in the train far exceeding its speed limit, East Japan Railway Co. said Tuesday.
At around 1:20 p.m. on Monday, the driver, in his 40s, lost consciousness while running between Higashi-Tokorozawa Station and Shinakitsu Station in the city of Tokorozawa, Saitama Prefecture. The train had left Tokyo Station and was bound for Fuchu-Honmachi Station in western Tokyo.
As a result, the train exceeded the section's reduced speed limit of 35 kph, running at a speed of 69 kph between the stations, JR East officials said, noting no one was injured in the incident.
The driver then noticed the speeding himself and activated the emergency brakes. The section's speed limit is usually set at 95 kph but had been reduced to 35 kph due to construction work on switches.
The driver was diagnosed with sleep apnea in 2014 and was undergoing treatment.
JR East has apologized for the incident, saying it will step up supervision of its employees.