Ford has received permission to tests its autonomous cars on public roads in California. The company will start this real-world testing in early 2016, a move which signals an important step forward in Ford's development of self-driving vehicles.

The company will let its autonomous Ford Fusion prototypes drive on the state's roads, mingling with other, human-controlled traffic, cyclists, trucks and pedestrians. The cars will also have to deal with other autonomous vehicles, as a number of other car makers already have permission to test there.

These include Alphabet's Google, whose driverless pods have been seen cruising the public roads for some time. As with Google, Ford will likely have engineers in its self-driving cars at all times, taking notes and fine-tuning the autonomous software each time it comes across new and unfamiliar scenarios.

California is one of just a handful of US states which allow driverless cars on its public roads. The others include Michigan, Nevada and Florida.

Other companies already allowed to test autonomous cars in California include Honda, Daimler, Mercedes Benz, Tesla, Nissan, Volkswagen and BMW. Technology companies like Apple and Uber are also working on self-driving cars, but haven't yet begun testing in public. In the case of Apple, which hasn't even announced publicly that it is working on a car, this move could be some time away yet.

Ford has repeatedly said that fully self-driving cars will be available to buy by the end of the decade, a timeline shared by Google and also rumoured to be Apple's intended release date, too. Ford recently showed off footage of its autonomous cars driving around a private test facility, Mcity, designed to mimic a real-world town. The cars can handle traffic lights, lanes and junctions without human intervention.