Google’s self-driving car is being hit “surprisingly often” by other drivers during its testing period, according to the company.
Writing on Medium, Google’s director of the self-driving car programme Chris Urmson said the collisions were happening when other drivers “were distracted or not paying attention to the road”.
Urmson detailed an incident in which people suffered whiplash when a Google car stopped at a junction and another vehicle “slammed into the back of us” at 17 mph.
“The other vehicle wasn’t so lucky; its entire front bumper fell off.”
Google has released a video showing a computer read-out of the collision (below). Urmson says: “As you can see… our braking was normal and natural, and the vehicle behind us had plenty of stopping distance – but it never decelerated.”
“This certainly seems like the driver was distracted and not watching the road ahead.
“Thankfully, everyone in both vehicles was okay, except for a bit of minor whiplash, and a few scrapes on our bumper. The other vehicle wasn’t so lucky; its entire front bumper fell off.”
Crash-per-miles-driven ratio “higher than we thought”
Google’s self-driving car has covered more than 1.7 million miles during a six-year road-testing period.
Urmson says: “We’re now driving enough – and getting hit enough – that we can start to make some assumptions about that real crashes-per-miles-driven rate; it’s looking higher than we thought.”
The Google cars have been hit by other vehicles 14 times since the beginning of testing in 2009, including 11 incidents where the car was struck from behind. Urmson says: “Not once has the self-driving car been the cause of the collision.”
He adds: “Instead, the clear theme is human error and inattention. We’ll take all this as a signal that we’re starting to compare favourably with human drivers.”
Google cars can “see” up to 200m in all directions
Google’s self-driving cars have “360º visibility and 100% attention in all directions at all times”, says Urmson. He adds that Google’s newest sensors can track other vehicles, cyclists and pedestrians to a distance of nearly 200m.
Google has been road-testing its driverless cars for six years, with the driverless technology retrofitted on to existing car models, such as the Toyota Prius and the Lexus models. Since 2014 the company has been testing its own Google Car model on Californian roads.
Following prototyping and testing, Urmson says Google aims to work with partners “to bring this technology into the world safely”.