(Reuters) -Alphabet Inc's self-driving technology unit Waymo said on Wednesday that some of its vehicles in San Francisco encountered dense fog and briefly pulled over to the side of the road.
The incident, which occurred at around 6.00 a.m. Pacific Time on Tuesday, impeded some traffic movement before the cars moved out of the area as the fog began to clear, Waymo said.
"We have software updates planned to improve our fog and parking performance to address such situations in the future," the company said in a statement to Reuters.
The company's cars use a system consisting of lidar sensors, cameras and radar sensors to perceive their surroundings.
Waymo in December said it was expanding its testing area to all of San Francisco city, after applying for a final permit it needs in California before it can sell fully autonomous rides.
Last week, General Motors (NYSE:GM)' robotaxi unit Cruise said it is recalling self-driving software in 300 vehicles after one of its driverless vehicles crashed into the back of a San Francisco bus.