Traffic cones confused a Waymo self-driving car. Then things got worse.

Traffic cones confused a Waymo self-driving car. Then things got worse.

But the Waymo vehicle soon became stuck farther down the road, which was lined with construction cones. The Waymo worker caught up to the vehicle, took over, and drove the paying passenger to his final destination. Waymo operates a limited ridehail service in Chandler, Arizona.

Autonomous vehicle experts who reviewed the video footage of the 41-minute trip posted on YouTube by the Waymo passenger say it shows a series of gaffes by the Waymo self-driving technology.

«The first one was understandable. The second was strange. The third one was jaw-dropping and the fourth one I threw up my hands,» Noah Goodall, a University of Virginia scientist who researches vehicle communication and automation, told CNN Business.

First, the Waymo vehicle paused at a stop sign rather than turning onto a street lined with cones. Waymo told CNN Business that guidance provided from one of its employees to revise the car’s trajectory was «improper,» and declined to elaborate. Waymo has remote workers who can provide information and directions to the self-driving vehicles. They can not take manual control of the vehicles.

The car then completed the turn, but soon stopped in the road, blocking part of a lane of traffic. Construction sites are known to be a challenge for fully autonomous vehicles because they rely on detailed maps of their environment to navigate safely. When the car’s environment changes, such as with traffic cones or lane closures, it can struggle to operate at its best.

Following a four-minute stop, it backed up slightly, further blocking a traffic lane. Human motorists had to cross a double yellow line to go around the Waymo vehicle. Some honked.

A construction crew removed a cone in the Waymo vehicle’s path, but the car remained stopped.

A few minutes later, the Waymo car pulled away, surprising a Waymo worker who was explaining to the van’s passenger, Joel Johnson, through the car’s audio system that roadside assistance was on its way. The worker encouraged Johnson to remain seated and keep his seat belt on.

«Are we moving?» the worker asked in a confused tone.

Further down the road, the Waymo van halted again, amid yet more cones. It was then that a Waymo roadside assistance vehicle arrived.

Johnson was told by the Waymo worker on the car’s audio system that the human driver would take over.

«You better hurry up, it’s going to escape,» Johnson warned the Waymo worker. Then, as the human driver approached, the Waymo car drove away again, but only a short distance.

«I don’t even know what’s going on anymore,» Johnson said in the video.

Johnson told CNN Business that he arrived about 20 minutes late at his destination following the mishaps, and received a Waymo refund.

«If you need to really be on time you don’t generally take Waymo yet,» Johnson told CNN Business in an interview.

Even so, Johnson, who said he’s taken 146 trips in Waymo vehicles, said he doesn’t think the public should be concerned with the safety of Waymo’s self-driving cars, and he continues to ride in the vehicles.

«I’ve seen so much impressive technology,» Johnson said of Waymo. «It seems disingenuous to write them off because of one incident.»

Waymo said in a statement that the situation was «not ideal,» and the self-driving car had received incorrect guidance, which made it challenging for the autonomous vehicle to resume its intended route. 

Bryant Walker Smith, who studies autonomous vehicles at the University of South Carolina, said he was surprised a command was never issued to halt the Waymo vehicle in place, so roadside assistance could take over.

«There wasn’t great coordination among the in-vehicle system, this remote monitoring capacity of the operator on the line and the on-ground assistance,» Smith said.