Google is creating sensors that will enable its driverless cars to automatically detect police vehicles in the area, documents have indicated.

Self-driving cars will be installed with technology that can identify approaching police cars and trigger an alert so that Google's vehicles can move out of the way or pull over to be questioned.

In a US patent filing, the internet giant has imagined a system that can recognise emergency services’ flashing lights. The sensors would identify red or blue colours, as well as the flashing sequence, to automatically detect police vehicles.