Punggol self-driving car accident a result of manual intervention by on-board safety officer: LTA

SINGAPORE: The recent collision of an autonomous vehicle (AV) with a road divider along Edgedale Plains in Punggol was a result of manual intervention by its on-board safety officer, the Land Transport Authority (LTA) said on Thursday (Jan 29) following a review of the accident.

"The review concluded that the AV detected an object that was not on the road. In response, the AV correctly manoeuvred into the adjacent lane as a precaution," LTA said in a statement.

The safety officer, observing that the vehicle was manoeuvring into a different lane without an obvious reason, then intervened to take manual control of the vehicle, and this led to the AV exiting autonomous mode.

"However, the safety officer was unable to complete the manoeuvre in time, which resulted in the vehicle colliding with the road divider," said LTA.

"A simulation of the incident showed that the AV would likely have completed the manoeuvre safely and resumed its intended course, had there been no manual intervention." 

As a result of the incident, LTA and the vehicle's operator ComfortDelGro (CDG) have reviewed the operating procedures for transitions between autonomous and manual driving, and when a safety officer should intervene while an AV is operating, to ensure safety for all, the authority said.

"This also highlights the importance of the familiarisation phase, where the AV familiarises itself with Singapore’s road conditions, and fleet operators and safety officers understand the behaviour of AVs, without any passengers on board," said LTA.

LTA added that it will lift the safety timeout it had implemented for CDG's self-driving vehicles, with CDG to resume autonomous operations in Punggol on Friday.

The incident occurred on Jan 17 while the vehicle was undergoing testing.

CDG told CNA on Jan 18 that the vehicle was undergoing routine mapping and familiarisation at about 3.10pm at Edgedale Plains when it "detected a small object on the road and responded accordingly".

"The safety operator on board proceeded to take over the steering of the vehicle manually. Unfortunately, the vehicle collided with the road divider during the manual takeover," said CDG, adding that there were no passengers on board, and no one was hurt in the incident.

CDG was given approval to commence trials of five five-seater AV shuttles last month.

In a joint statement issued in response to LTA's findings, the National Private Hire Vehicles Association (NPHVA), the National Taxi Association (NTA) and the National Transport Workers' Union (NTWU) said that they "support LTA's call to review the AV-to-manual transition process and for fleet operators and safety operators to develop a deeper understanding of AV behaviour".

"To this end, we reiterate the importance of adequate training for all AV personnel," the associations said.

"We also emphasise the importance of ensuring the safety of our drivers inside AVs during the pilot phase."

NPHVA, NTA and NTWU added that trial periods should go beyond technology testing and route mapping.

The associations said: "They must also provide personnel with sufficient time to familiarise themselves with the broader industry landscape and the systems they operate.

"This is especially critical as autonomous vehicle deployment remains in the familiarisation phase, where continuous learning and improvement, for both technology and people, are essential."