There's so much intrigue into Google's self-driving car's accident with a public bus on El Camino Real near the company's hometown of Mountain View, Calif. on Feb. 14 that the tech company is following up with some details.
Google provided Engadget with its expanded view of the accident from its February monthly autonomous driving report, attributing it to a "normal part of driving," while already making software adjustments to prevent such an issue from lingering into the future.
"On February 14, our vehicle was driving autonomously and had pulled toward the right-hand curb to prepare for a right turn. It then detected sandbags near a storm drain blocking its path, so it needed to come to a stop. After waiting for some other vehicles to pass, our vehicle, still in autonomous mode, began angling back toward the center of the lane at around 2 mph — and made contact with the side of a passing bus traveling at 15 mph," Google offered Engadget from its February monthly autonomous driving report. "Our car had detected the approaching bus, but predicted that it would yield to us because we were ahead of it."
Google adds that the test driver of its Lexus RX450h autonomous vehicle expected the bus to yield, while the bus driver thought the self-driving car was going to stay put — two assumptions that eventually led to the collision, in the same way accidents occur involving two assuming human drivers.
"This is a classic example of the negotiation that's a normal part of driving — we're all trying to predict each other's movements," Google continued. "In this case, we clearly bear some responsibility, because if our car hadn't moved there wouldn't have been a collision. That said, our test driver believed the bus was going to slow or stop to allow us to merge into the traffic, and that there would be sufficient space to do that."
Immediately following the Feb. 14 accident, the team working on Google's self-driving car knew it had changes to make.
"We've now reviewed this incident (and thousands of variations on it) in our simulator in detail and made refinements to our software," Google's statement continued. "From now on, our cars will more deeply understand that buses (and other large vehicles) are less likely to yield to us than other types of vehicles, and we hope to handle situations like this more gracefully in the future."
While the entire auto industry will continue to view the growth of autonomous driving technology with a sharp lens, this was a minor incident — one from which Google seemingly learned plenty.
