The technology is still undergoing tests, and the firm hasn't announced when exactly the vehicles will become an addition to public roads because engineers are still ironing out a number of issues.

But, that hasn't stopped the project's director Chris Urmson and his team demonstrating its potential to fans in Mountain View. 

Mr Urmson is also hopeful the cars will be roadworthy within the next five years. 

One of the features said to be delaying the car's release is its inability to cope in heavy rain or snow.

An insider told MIT Technology Review that the current prototype cars are very reliant on maps to navigate and can’t react like a human driver, dodging potholes and other hazards. 

The latest official figures from Google revealed the cars have already driven themselves for more 700,000 miles (1,126,540km), but they struggle to cope in snowy conditions and can't negotiate heavy rain.

Mr Urmson said this is because the detection technology is not yet strong enough to separate certain objects from weather conditions.

While the cars’ cameras can spot a traffic light changing, they can be confused by strong sunlight.

They don’t distinguish between an empty plastic bag - which could be easily driven over - or a rock, so cars must drive around both. They also can’t detect uncovered manholes or potholes.

Mr Urmson said: ‘I could construct a construction zone that could befuddle the car.’

(dailymail.co.uk)