Automated driving systems are more effective than the easily distracted human mind, Chris Urmson, director of Google's driverless car project said following reports that a number of Google cars had been in accidents since testing began.
Smartphones and other in-car distractions can fatally hinder a driver's concentration however "a self-driving car has people beat on this dimension of road safety," Urmson wrote in a blog post.
With 360-degree visibility, the sensors in Google's fleet can keep track of other vehicles, cyclists, and pedestrians to a distance of nearly two football fields, he claimed.
Yet even Google's cars have been involved in 11 accidents in the six years the company has been testing them, Urmson admitted. The fleet of over 20 cars has covered 1.7 million miles of autonomous and manual driving in that time.
In all cases, there was only light damage and no injuries - and the Google car was never the cause of the accident, he wrote.
Urmson's response comes after reports of US road accidents involving Google's cars.
Three of the firm's high tech Lexus SUVs were involved in collisions. Delphi's autonomous car also had an accident, bringing the tally up to four since September, according to the Associated Press.
Urmson highlighted an issue that Google and other autonomous driving hopefuls must address before self-driving cars go mainstream: how to recognise and respond to the wacky driving habits of humans.
Take intersections. To account for the possibility of another driver running a red light, Google has programmed its cars to pause briefly after a light turns green before proceeding into the intersection.
With their software and sensors, Google's cars can take action earlier and faster than an alert human driver, he wrote. But sometimes they can't overcome the realities of speed and distance, and they get hit just waiting for a light to change.
Out of the 11 reported accidents, Google's cars have been hit from behind seven times, mostly at traffic lights.
The company's cars have also been side-swiped a couple of times and hit by a car rolling through a stop sign, he added.
Google's cars now average 10,000 miles of autonomous driving a week, mostly on city streets near Google's headquarters in Mountain View, California.