As per NHTSA (2013) report, autonomy level in automated vehicles.
|0||No Automation. The driver is in complete and sole control of the vehicle controls (brake, steering, throttle, and motive power) at all times.|
|1||The autonomy of one or more primary control functions. E.g. the vehicle assists automatically with pre-charge braking to enable the driver to stop faster than possible by acting alone.|
|2||The autonomy of at least two primary control functions is designed to work in unison to relieve the driver of control of these functions. E.g. the combined function of active cruise control and lane centering.|
|3||Limited Self-Driving Automation: Vehicles at this level of automation enable the driver to cede full control of all safety-critical functions under certain traffic or environmental conditions and in those conditions to rely heavily on the vehicle to monitor for changes in those conditions requiring transition back to driver control. The driver is expected to be available for occasional control, but with a sufficiently comfortable transition time.|
|4||Full Self-Driving Automation: The vehicle is designed to perform all safety-critical driving functions and monitor roadway conditions for an entire trip. It is designed so that the driver will provide only destination or navigation input. The driver is not expected to be available for control at any time during the trip. This includes both occupied and unoccupied vehicles.|
In the below figure, the development expected for automated vehicles technology and the autonomy level over time has been shown:-