SEOUL - A signal failure was the cause of a subway collision in South Korea, indicating the accident came from human errors, the Seoul government office said Saturday.

A subway train in the capital, Seoul, crashed into a train at a station, injuring 200 people although no one was killed. [Photo/Xinhua]

The office told a press briefing that traffic signs did not work and caused a failure in automatic train stop (ATS).

One train pulling into the Sangwangshimri station in the east of Seoul rear-ended another train at 3:30 p.m. local time Friday, leaving 243 people injured. Most of them sustained minor injuries such as bruises and abrasions, but one was treated for a brain hemorrhage and two for a fracture. No fatalities were reported.

The ATS, installed in all Seoul subways, is designed to keep the distance between trains at least 200 meters apart. When a train nears 200 meters of another, the train automatically stops.

According to the Seoul government, the traffic sign was blue at that time, causing the ATS not to work. In normal times, the signal should have been red to tell the driver to stop the train or the ATS to work.

The moving train, which was running at the speed of 68 km per hour, made an emergency stop, but it smashed into the back of the other train at the speed of 15 km per hour as the braking distance is too short.

Based on a probe into the traffic signal log, the breakdown occurred at 3:10 a.m. on Friday. It was repaired at 4:25 a.m. Saturday. The Seoul government planned to conduct special safety checks into all Seoul subways from next Wednesday to prevent the recurrence of such accident.

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