Google car pulled over by police
This Google self-driving car was pulled over my a curious policeman for driving too slowly Google

Google might be trying to make its autonomous cars drive just like humans, but here's one thing not many of us can admit to. One of its self-driving cars has just been pulled over for driving too slowly.

A photograph published on Twitter by David Weekly, head of Alphabet's 'rapid rollout lab', showed the car pulled over to one side and a motorbike policeman talking to its driver/minder. It isn't clear if the photo was staged, or if it was taken right outside the offices of Alphabet, Google's parent company.

Google said the cars are currently limited to travel no faster than 25mph, which in some areas may be considered dangerously slow and a hazard for other vehicles trying to overtake. The fleet of autonomous cars have so far clocked up more than 1.2 million autonomous miles while driving for the equivalent of 90 years.

In a blog post, the company said: "Driving too slowly? Bet humans don't get pulled over for that too often. We've capped the speed of our prototype vehicles at 25mph for safety reasons. We want them to feel friendly and approachable, rather than zooming scarily through neighbourhood streets.

"Like this officer, people sometimes flag us down when they want to know more about our project. After 1.2 million miles of autonomous driving... we're proud to say we've never been ticketed!"

The emphasis on friendliness is obvious from the design of the two-seater electric cars, but they are also being programmed to act more assertively when necessary, such as at a four-way-stop junction when no driver is sure who has priority. It is believed that fully autonomous cars like this will be available for consumers to use by the end of the decade; this is also the goal for a semi-autonomous car project currently being worked on by Apple.