LEVEL 0: No automation.
The human driver controls all aspects of driving all the time.
LEVEL 1: Driver assistance.
One aspect of vehicle motion, such as steering or acceleration/deceleration, is executed by an assistance system and a human driver.
LEVEL 2: Partial automation.
Steering and acceleration/deceleration can both be executed by the assistance system, but the human driver must be ready to take full control in an emergency and is ultimately responsible for whatever the vehicle does.
LEVEL 3: Conditional automation.
All aspects of driving can be performed by the system. Vehicles self-manage steering and acceleration/ deceleration, and also monitor the environment around them, but the human driver must intervene upon request.
LEVEL 4: High automation.
The system can manage all aspects of driving even if the human driver doesn’t respond to an intervention request. Vehicles at this level are truly ‘driverless’; however, the option to manually override the assistance system remains.
LEVEL 5: Full automation.
Vehicles at this level don’t require a driver to be present at all; they don’t have steering wheels or pedals and require no human intervention.