Autonomous shuttle in Punggol apparently brakes hard at traffic light for no reason

An autonomous vehicle (AV) apparently braked hard suddenly as it approached a traffic light that was showing green in Punggol, causing the drivers behind to apply the brakes of their vehicles as well.

The incident apparently occurred on Aug. 13, 2026, at around 11:15am.

A Grab logo could be seen at the AV shuttle's rear.

Dashcam footage of the incident was shared online recently, after a video of an AV almost hitting a schoolgirl who was crossing the road in Punggol was put up on social media, sparking concerns with self-driving technology and its testing on public roads.

What video showed

The footage of the AV braking without encountering any obstacle was taken along Punggol Field.

As seen in the footage, the AV braked hard even when it had the right of way and did not appear to encounter any obstacles on the road.

About 3 seconds later, the traffic light turned red.

The vehicle recording the scene could be seen braking hard to avoid rear-ending the AV that had come to an almost complete stop.

The rear camera of the vehicle recording the scene captured footage of a van behind having to brake hard as well to avoid a collision.

The driver who supplied the video wrote, "lucky i kept a safe distance & the driver behind me was alert too."

LTA response

In response to Mothership's queries, the Land Transport Authority (LTA) said it is aware of online videos showing the driving behaviour of AVs on roads in Punggol.

"We are reviewing the incidents with the respective AV operators to establish the circumstances and identify any necessary improvements," LTA said.

AVs deployed on public roads are regulated under the sandbox set out in Road Traffic (Autonomous Motor Vehicles) Rules 2017 and are required to comply with all traffic rules and LTA’s safety and operational requirements, LTA added.

The authority has also worked with the traffic police to establish a set of protocols to respond to and manage any accidents involving AVs.

All authorised AV operators are required to maintain liability insurance covering third-party death, bodily injury and property damage caused by, or arising out of the use of the AVs, including passengers, LTA noted.

LTA may take regulatory actions, such as suspending or cancelling the authorisation to operate on public roads, if regulatory requirements are not met.

LTA also said:

"The ongoing pilot in Punggol allows operators to test and progressively refine their technology under local traffic conditions to comply with traffic rules and safety requirements.

This also highlights the importance of testing, where the AV familiarises itself with our road conditions with the safety operator on board.

We will continue working with AV operators to address issues identified during the pilots and ensure that AV operations meet the required safety standards.

From next month, Singapore will publish a quarterly report on all our AV deployment efforts. This is to ensure transparency and strengthen public confidence in AVs as we scale up."

In response to media queries, Grab said: "Safety operators are on board at all times to step in when needed and provide continuous feedback to guide system refinements."

Grab added that it is "thoroughly reviewing each instance" with LTA and its partner, WeRide.

Members of the public can report incidents online.

Self-driving vehicle incidents

This was not the first instance of an AV shuttle behaving in an apparently erroneous manner.

On Nov. 5, an AV shuttle making a left turn nearly hit a schoolgirl, before veering away and braking.

In response, LTA directed Grab to pause some of its AV testing until investigations are concluded.

Another incident on Nov. 5 involved an AV shuttle under ComfortDelGro making a U-turn and not giving way to an oncoming vehicle going straight.

As a precautionary measure, LTA directed ComfortDelGro to pause U-turns at the junction pending the outcome of its review.

LTA also said the incident occurred while ComfortDelGro was conducting AV testing along a route intended for its enhanced on-demand service and the route was not part of its existing shuttle route.

Grab currently operates two routes in Punggol, while ComfortDelGro operates one.