As part of its recently released Federal Automated Vehicles Policy, the DOT (Department of Transportation) provided an up-to-date classification of autonomous vehicles (AVs), also known as self-driving cars. Based on the definitions as stated by SAE International, which sets automotive and aerospace standards, the new definition supersedes the original released by NHTSA (National Highway Traffic Safety Administration) in May 2013.
While the original NHTSA definition provided five stages of automation, from totally human-controlled to totally automated, the new SAE definition has six stages. Despite an additional stage, the SAE definition is far simpler and easier to understand than the original, which was somewhat confusing in places.
Levels of Automation 2013 (NHTSA)
No Automation (Level 0): The driver is in complete and sole control of the primary vehicle controls — brakes, steering, throttle and motive power — at all times.
Function-Specific Automation (Level 1): Automation at this level involves one or more specific control functions. Examples include electronic stability control or pre-charged brakes, where the vehicle automatically assists with braking to enable the driver to regain control of the vehicle or stop faster than possible by acting alone.
Combined Function Automation (Level 2): This level involves the automation of at least two primary control functions designed to work in unison to relieve the driver of control of those functions. An example of combined functions enabling a Level 2 system is adaptive cruise control in combination with lane centering.
Limited Self-Driving Automation (Level 3): 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 to rely heavily on the vehicle to monitor for changes in those conditions that would require a transition back to driver control. The driver is expected to be available for occasional control, but with a sufficiently comfortable transition time. The Google car is an example of limited self-driving automation.
Full Self-Driving Automation (Level 4): The vehicle is designed to perform all safety-critical driving functions and monitor roadway conditions for an entire trip. Such a design anticipates that the driver will provide destination or navigation input but will not be available for control at any time during the trip. This level includes both occupied and unoccupied vehicles.
Levels of Automation 2016 (SAE)
At SAE Level 0, the human driver does everything.
At SAE Level 1, an automated system on the vehicle can sometimes assist the human driver in conducting some parts of the driving task.
At SAE Level 2, an automated system on the vehicle can actually conduct some parts of the driving task, while the human continues to monitor the driving environment and performs the rest of the driving task.
At SAE Level 3, an automated system can both actually conduct some parts of the driving task and monitor the driving environment in some instances, but the human driver must be ready to take back control when the automated system requests.
At SAE Level 4, an automated system can conduct the driving task and monitor the driving environment, and the human need not take back control, but the automated system can operate only in certain environments and under certain conditions.
At SAE Level 5, the automated system can perform all driving tasks under all conditions where a human driver could perform them.
What it means to you: Although the federal government has been slow to address self-driving cars, the DOT’s new policy statement and the introduction of easier-to-understand levels of automation indicate the government’s eagerness to become a part of the AV development process.