Google does not deny that its self-driving cars had been involved in 11 road accidents. On Monday, the tech giant revealed this count occurring in a span of six years, USA Today reported.

According to the outlet, the Associated Press has reported accidents involving self-driving cars since September, all taking place in California. Three of these cars are said to be operated by Google, while the fourth one is reportedly owned by auto supplier Delphi.

While such instances could spark alarm at their very thought, Chris Urmson, director of Google's self-driving car program, clarified in an article, "Over the 6 years since we started the project, we've been involved in 11 minor accidents (light damage, no injuries) during those 1.7 million miles of autonomous and manual driving with our safety drivers behind the wheel, and not once was the self-driving car the cause of the accident."

Who's responsible for these incidents, then?

Urmson claimed that rear-end crashes are the most frequent accidents in America, "We've been hit from behind seven times, mainly at traffic lights but also on the freeway. We've also been side-swiped a couple of times and hit by a car rolling through a stop sign."

"And as you might expect, we see more accidents per mile driven on city streets than on freeways; we were hit 8 times in many fewer miles of city driving," the director went on.

As told by Time, in Google's stretch of 1.7 million miles, its accident rate comes at about 6.5 per million miles traveled. The outlet tells that such figure is higher than the 2.8 "property-damage-only" accidents per million miles traveled involving passenger cars in 2012, based on data from the National Highway Traffic Safety Administration.

However, self-driving cars are conceptualized in order to reduce accidents, The Next Web noted. Citing information from the NHTSA, the outlet said "driver mistakes" cause 94% of these road mishaps in the United States.

On top of the usual distraction stemming from electronic device usage, Google was able to spot other forms of reckless driving: people weaved in and out of their respective lanes, some read books and one even played a trumpet.

Nevertheless, Urmson has pointed that accidents are inevitable -- whether humans or robots are involved, Popular Science noted. The outlet comes to a resolution, "So maybe the old adage is true: the perfect system is one with no users. Only when people have been eliminated can robots finally drive in safety."

Meanwhile, Google's self-driving cars are expected to hit the market by 2020, Time said.

What do you think of Google's autonomous vehicles? Sound off in the comments section.