Autonomous Driving Levels and What They Mean to You

SAE International (formerly known as the Society of Automotive Engineers) and the National Highway Traffic Safety Administration recognize six tiers of autonomous driving capability in cars: Level 0, no autonomy; Level 1, driver assistance; Level 2, partial automation; Level 3, conditional automation; Level 4, high automation; and Level 5, full automation.

Related: Which Cars Have Self-Driving Features for 2020?

It bears noting that no passenger car in the U.S., as of this writing, is rated higher than Level 2. The 2020 Audi A8 full-size luxury sedan had been expected to debut Level 3 technology before those plans were scuttled by regulatory obstacles. Make no mistake, though: It’s not a question of if these higher tiers of autonomy will make it to a production car in America, but when — eventually leading to full self-driving capability.

To give you an idea of where the technology is taking us, here are more in-depth explanations of the six levels of autonomous driving and what they mean to you, the “driver”:

Level 0: No Autonomy

Zero autonomy; the driver performs all driving tasks.

What It Means to You

It’s all you, man. You’re doing all the driving with no technological assistance.

Level 1: Driver Assistance

The vehicle is controlled by the driver, but some driver assist features may be included in the vehicle design.

What It Means to You

An advanced driver assistance system, or ADAS, can sometimes assist the human driver with either steering or braking and accelerating — but not both simultaneously.

Level 2: Partial Automation

The vehicle has combined automated functions, such as acceleration and steering, but the driver must remain engaged with the driving task and monitor the environment at all times.

What It Means to You

An ADAS on the vehicle can control both steering and braking/accelerating simultaneously under some circumstances. The human driver must pay full attention, i.e., “monitor the driving environment” continually and perform the rest of the driving tasks.

Level 3: Conditional Automation

A driver is a necessity but is not required to monitor the environment. The driver must be ready to take control of the vehicle at all times with notice.

What It Means to You

An automated driving system, or ADS, can perform all aspects of the driving task under some circumstances. In those circumstances, the human driver must be ready to take back control any time the ADS requests the human driver to do so. In all other circumstances, the human driver performs driving tasks.

Level 4: High Automation

The vehicle is capable of performing all driving functions under certain conditions. The driver may have the option to control the vehicle.

What It Means to You

An ADS on the vehicle can perform all driving tasks and monitor the driving environment — essentially, do all the driving — in certain circumstances. The human need not pay attention in those circumstances.

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Level 5: Full Automation

The vehicle is capable of performing all driving functions under all conditions. The driver may — or may not — have the option to control the vehicle.

What It Means to You

Sit back and enjoy the ride. An ADS on the vehicle can do all the driving in all circumstances. The human occupants are just passengers and need never be involved in driving.

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