Stop hitting the horn, the robot at the wheel can't hear or see you

AS car accidents go, it wasn't much: 12 minutes before noon on a cool June day, a Chevrolet Bolt was rear-ended as it crawled from a stop light in downtown San Francisco.

What made this fender bender noteworthy was the Bolt's driver: a computer. In California, where companies such as Cruise Automation Inc and Waymo are ramping up testing of self-driving cars, human drivers keep running into them in low-speed fender benders.

The run-ins highlight an emerging culture clash between humans who often treat traffic laws as guidelines and autonomous cars that refuse to roll through a stop sign or exceed the speed limit.