Global automotive experts emphasize that most advanced vehicle features available today are driver assistance systems, requiring human supervision, rather than truly autonomous driving technologies.
The Society of Automotive Engineers (SAE), an American engineering body that has set technical standards for the automotive industry since 1905, established a six-level classification system to clarify the progression of vehicle automation. This standard distinguishes between features that assist a human driver and those that allow a vehicle to drive itself.
Legal and regulatory hurdles currently prevent the widespread activation of higher levels of autonomy, even as some manufacturers claim their vehicles are ready for full self-driving capabilities.
The SAE’s framework divides vehicle automation into two primary categories: “driver support systems” (Levels 0-2) where the human remains in control, and “automated driving systems” (Levels 3-5) where the system takes over.
Levels 0 to 2 are not considered genuinely autonomous. In these systems, the human driver is always responsible for supervising and maintaining control of the vehicle.
At Level 0, there is no automation, meaning the driver is entirely responsible for all aspects of control, such as steering, braking, and acceleration. While a car might offer warning systems like blind spot alerts or automatic emergency braking, these are momentary interventions or alerts and do not count as driving automation.
Level 1 introduces driver assistance, where the vehicle provides at least one active assistance feature that intervenes in either steering or acceleration/braking in specific situations. Common examples include adaptive cruise control or lane-keeping assist.
Level 2, known as partial assistance, combines multiple Level 1 functions. The car can simultaneously control steering, acceleration, and braking in defined scenarios, such as on highways. However, the driver must remain vigilant and ready to intervene at any moment, necessitating “eyes-on” supervision even if their “hands-off” the wheel.
A significant technological leap occurs from Level 3 onwards, where the responsibility for driving begins to shift from the human to the machine under specific conditions.
Level 3, or conditional automation, allows the car to assume total control over steering, braking, and acceleration in specific, approved conditions. The driver can become a passenger, potentially taking their hands off the wheel and eyes off the road, but they must be prepared to reassume control when prompted by the system.
Level 4, high automation, means a vehicle is considered fully autonomous in most circumstances but operates only within “geo-limited” or “geo-fenced” areas. Within these zones, which require detailed high-definition maps and suitable weather conditions, the vehicle does not require human intervention, even allowing the driver to sleep. These systems are foundational for future “robotaxis.”
Level 5 represents total automation, the highest level. A Level 5 car is completely automated, capable of operating on any road and in all conditions without any human input. Many vehicles at this level are expected to entirely omit steering wheels and pedals.
Currently, most new cars from manufacturers like Tesla, Volvo, Mercedes, and Audi feature Level 2 capabilities. Tesla’s well-known “AutoPilot” system, for instance, is classified as Level 2.
Level 3 remains a contentious area. Some experts, including those at Ford, view the transition of control from the car back to the human as complex, leading Ford to announce plans to focus directly on Level 4. In contrast, Honda has launched Level 3-capable vehicles, though their operation is extremely restricted by law, such as only in Japan during slow traffic.
While Tesla’s “Full Self-Driving” (FSD) system is undergoing advanced beta testing, it is expected to be classified as Level 3 upon official release, despite its name. Authorization for Level 3 systems on public roads, such as highways at low speeds, is being slowly implemented in various regions. However, true autonomy at Levels 4 and 5 is still considered several years away.