The near-collision was between a Lexus RX400h operated by Google and an Audi Q5 crossover operated by Delphi Automotive Plc.
The cars were driving themselves, but each also had a person behind the wheel as backup. The Google vehicle reportedly cut off the Audi as it began to change lanes.
The incident is believed to be the first involving two automated driving vehicles, and no collision took place, as the Audi aborted its lane change to avoid the Google vehicle.
A spokeswoman for Delphi, Kristen Kinley, told CNNMoney that this is an example of how self driving cars can effectively avoid accidents.
"Our car saw the Google car move into the same lane as our car was planning to move into, but upon detecting that the lane was no longer open it decided to terminate the move and wait until it was clear again," she said.
"The headline here is that two self-driving cars did what they were supposed to do in a fairly ordinary everyday driving scenario," a spokeswoman for Google stated, echoing Kinley’s sentiment.
In all previous collisions involving self-driving cars, the automated prototypes were not found to be at fault. All of the incidents were minor, and most involved the vehicles being rear-ended by human drivers, mainly at intersections.
Delphi is currently running two Audi test vehicles, while Google has more than 20 in their fleet of Lexus prototypes.