Google has built its first fully functioning self-driving vehicle and it will be driving the streets of California in the new year.The search engine giant posted a picture of the bubble-shaped car on its website with the message: “The vehicle we unveiled in May was an early mockup – it didn’t even have real headlights!

Google Unveils 'Complete' Driverless Car

“Since then, we’ve been working on different prototypes-of-prototypes, each designed to test different systems of a self-driving car – for example, the typical “car” parts like steering and braking, as well as the “self-driving” parts like the computer and sensors.

“We’ve now put all those systems together in this fully functional vehicle – our first complete prototype for fully autonomous driving.”

The company added that the car will be driven over the Christmas period on a test track before heading out onto the roads of northern California.

A safety driver will be onboard to “oversee the vehicle for a while longer, using temporary manual controls as needed”.

In May, Google announced that it would begin developing and building its own vehicles after adapting existing models with its self-driving technology.

Lexus SUVs and Toyota Prius cars have driven hundreds of thousands of miles on public roads using the special equipment.

Google says it plans to make 100 prototype cars that are operated using two simple buttons – go and stop – and navigate using GPS, sensors and camera data.

Google co-founder Sergey Brin said in May: “The main reason we wanted to develop this prototype vehicle is that we can do a better job than we can do with an existing vehicle.

“The experience feels different. You’re just sitting there, no steering wheel, no pedals – for me it was very relaxing. In about 10 seconds after getting in, I forgot I was there. It reminded me of catching a chairlift by yourself, a bit of solitude I found really enjoyable.”

Today’s announcement marks another step towards the use of autonomous vehicles being developed by a number of companies.

In March, Ford unveiled a self-driving car that takes 2.5 million measurements every second.

And in Milton Keynes next year, an initial batch of 20 autonomous pods will begin running on lanes separated from pedestrians from the train station to the town in a project that could be rolled out to other towns and cities around the country.