A train operating under automatic control at Toranomon Hills Station on the Tokyo Metro Hibiya Line overran its stopping position by approximately 300 meters, prompting the conductor to apply the emergency brake. Trains that subsequently returned to Toranomon Hills Station discharged all passengers and terminated service, suspending service on part of the Hibiya Line for approximately 50 minutes.
At around 7:55 a.m. on the 19th, a 7-car Tokyo Metro Hibiya Line train failed to stop at its designated stopping position after departing Toranomon Hills Station toward Kita-Senju and overran by approximately 300 meters. The train was operating automatically under ATO, but the automatic brake did not engage, so the conductor applied the emergency brake and stopped the train.
The train returned to Toranomon Hills Station, where all passengers were discharged, and terminated service. Service on part of the Hibiya Line was suspended for approximately 50 minutes, affecting around 34,000 people.
The ATO settings were reportedly still configured as they had been before the opening of Toranomon Hills Station in June 2020, and Tokyo Metro is investigating the detailed cause.