Google acknowledged May 11 that its self-driving cars have been involved in 11 accidents since the company began working on the technology approximately six years ago. The company claims, however, that in none of the accidents have the cars been at fault.
“During … 1.7 million miles of autonomous and manual driving with our safety drivers behind the wheel … not once was the self-driving car the cause of the accident,” Chris Urmson, head of the Google self-driving car project, wrote in a blog post published on the website Medium.
Google addressed the issue after the Associated Press reported that Google had filed paperwork for three collisions in California, where reporting accidents is part of the agreement permitting the company to test the cars on public roads. It now appears that of the 48 self-driving cars in California, four have been in accidents since September of 2014.
However, Google has declined to make public the full records of the accidents involving its cars, meaning the public has only the company’s word regarding the severity of the collisions. The Department of Motor Vehicles could not comment, since crash information is private in California.
A person familiar with the crashes, who spoke to the AP on condition of anonymity because of a lack of authorization to reveal the information, said that all four accidents in California have occurred when the test car was moving at 10 miles per hour or below. Two occurred while the cars were in self-driving mode, whereas the other two occurred while the driver (still required to be behind the wheel) was steering.
Google has emphasized from the beginning of its program that self-driving technology has the potential to prevent accidents. The causes of car crashes are many, of course — mechanical failures are a factor in between 12% and 13% of auto accidents, and unpredictable factors such as road conditions may also contribute. Driver error, however, is at play in a full 94% of crashes. “That’s why so much of the enthusiasm for self-driving cars has focused on their potential to reduce accident rates,” Urmson reiterated.
Nationally, property-damage-only crashes occur at a rate of about 0.3 per 100,000 miles driven, according to National Highway Traffic Safety Administration data. If Google has had 11 such accidents in 1.7 million miles, the rate for the company’s self-driving cars would be about 0.6 per 100,000 miles driven. It’s difficult to make an accurate comparison, however, because as many as five million of these minor accidents are thought to go unreported each year.