Google’s self-driving cars may have notched up 700,000 accident-free miles without anyone needing to press the big red Stop button, but project director Chris Urmson’s personal deadline to have the cars on sale to the public is still five years away, reports the MIT’s Technology Review.

Most tech-heads know that the cars rely on inch-perfect modelling of the specific streets they will use, the cars unable to drive anywhere else, but the piece revealed that this is just one of the challenges ahead …  expand full story