Google has created a virtual simulation of the entire Californian road system to test out its driverless vehicles.

The technology company wants the state's regulators to base its decision to certify them on this 'Matrix-style' world, the Guardian reports.

So far, the cars have driven more than four million miles inside the virtual world, where they have faced similar challenges that are encountered in the real world, such as lane-weaving motorists, wobbly cyclists and unpredictable pedestrians.

California's regulations state that autonomous vehicles should be tested under controlled conditions that provide a realistic representation of real-world driving.

Ron Medford, Google's safety director for the self-driving car programme, wrote a letter to the state's officials earlier this year claiming the virtual-reality simulation is more reliable than conventional testing methods.

Google spokeswoman Katelin Jabbari said: "In a few hours, we can test thousands upon thousands of scenarios which in terms of driving all over again might take decades."