But what sets these vehicles really apart is the lack of controls that have been part of every car produced since the dawn of the horseless carriage. Only a handful of the Google's prototypes will be equipped with steering wheel and pedals. After that, they will only feature an on/off button and controls allowing the riders to input a destination—by voice, of course. "Seniors can keep their freedom even if they can't keep their car keys. And drunk and distracted driving could become a thing of the past," explains Chris Urmson, the head of Google's autonomous vehicle programme.

The technology giant is planning only to produce 100 autonomous prototypes, a quirky little electric vehicles with a range of 100 miles and a top speed of 25mph. From the outside, they look like a cross between a Volkswagen Beetle and a Smart Fortwo microcar. They will feature a soft nose and a flexible windscreen—just in case they hit a pedestrian.