levels of driving automation

The levels of driving automation are a scale published by SAE International in its recommended practice J3016, first issued in 2014 and refined together with the International Organization for Standardization in 2021. It runs from Level 0, no driving automation, to Level 5, full driving automation. The US National Highway Traffic Safety Administration uses the same six levels to explain automated vehicles to the public.

At Levels 0 to 2 the person is driving. The car may warn, brake, or help with steering or speed, and at Level 2 it can steer and control speed together, but the driver must stay fully engaged and attentive throughout. At Level 3 the system drives in set conditions, while the person in the driving seat must be ready to take over whenever it asks.

At Level 4 the system is fully responsible for the driving within a limited service area, and the people inside are only passengers: no human driver is needed. Level 5 would do the same everywhere, under all conditions and on all roads. NHTSA notes that Level 3 technology is not widely available for consumers to buy, and that Level 4 and Level 5 technology is not on sale to consumers at all.