Self-driving bus damaged in accident in southwestern Japan due to 'human error'

OITA -- A self-driving bus being tested in the city of Oita in southwestern Japan was damaged in an accident after a driver on board to ensure safety made an error, developers said.

The accident reportedly occurred at about 2:20 a.m. on Sept. 25, when the bus was turning left at an intersection. According to Oita Chuo Police Station and the municipal government's town planning division, the bus hit the curb, scraping the rear left wheel and the fender. There was a driver on board at the time, along with three others including at least one city official, but none of them were injured.

Gunma University, which developed the bus, said that there were no problems with the automatic driving system itself, and that an error on the part of the driver was responsible. The Oita Municipal Government plans to continue testing the bus.

City officials said the bus was being tested in preparation for experimental operations on the "Oita Kyan Bus" Route in the central city between Oct. 6 and 14. According to Takeki Ogitsu, an associate professor at Gunma University, the bus was being driven autonomously using GPS and a laser sensor, under the constant observation of a driver, who could take over at any time if necessary.

Ogitsu said that the GPS signal was lost after being blocked by a building when the bus was turning left, and so the bus was switched to the laser sensor alone, which was less accurate. The driver didn't notice that the bus was too close to the curb before the vehicle hit it.

In a separate accident in September 2017, a self-driving minivan developed by Gunma University hit a guard rail in the city of Kiryu in the eastern Japan prefecture of Gunma during experimental operations.

(Japanese original by Toru Shirakawa and Hyelim Ha, Oita Bureau)