The Different Levels of Automation
The technological evolution away from manual driving to fully automated vehicles is underpinned by a complicated, time-consuming process involving innovations in lots of different technical disciplines. The Society of Automotive Engineers (SAE) has divided this process into six levels. Level 0 denotes traditional, conventional driving. The driver controls the vehicle and additional systems help them to process information by providing orientation (navigation system with route display) or warnings (e.g., blind spot assistant or acoustic parking assistant). Level 1 denotes assisted driving, where assistance systems take over specific driving tasks in certain situations. This includes things like speed control, distance control, or active parking assistants that act like a digital butler in that they handle the entire process of parking the vehicle in a parking space. Level 2 is semi-automated driving, where the vehicle keeps to its lane under defined conditions and independently brakes or accelerates.
Level 3 is highly automated driving, which enables the driver to temporarily turn their attention away from driving the vehicle and monitoring traffic. The vehicle drives itself in the Operational Design Domain (ODD) set by the manufacturer, but the person behind the wheel is still required to take control at short notice if the system requires it. This level marks the point at which the person in the driver’s seat takes on a hybrid role, switching between being a traditional driver of the vehicle and a vehicle user while the vehicle is moving in automated mode. A current example of Level 3 automation is the Drive Pilot system from Mercedes- Benz. On December 2, 2021, the German Federal Motor Transport Authority issued the world’s first type approval for this kind of automatic lane guard system. Its use in the Mercedes- Benz S-Class is currently still restricted to a speed of 60 km/h on freeway-type roads, and is only allowed in daylight, with good visibility, and if there is no frost. The person behind the wheel must always be ready to take over control of the vehicle if prompted to do so.
The next level up, Level 4, denotes fully automated driving, which is when the person behind the wheel relinquishes all driving duties to the vehicle and becomes a passenger. The vehicle manages many stretches of road by itself, and after handing over control to the vehicle the driver is allowed to turn their attention away from what is happening on the road. The system must be able to detect the limits in good time, so as to ensure it can independently adopt a safe state in compliance with the regulations and prevent damage by parking at the side of the road or on a shoulder. In effect, it should no longer be possible to hold occupants liable for any violations or damage caused when the vehicle is in fully automated mode. Vehicle driving at Level 4 is a much broader concept than Level 3 and it contains only a few specifically defined exclusion criteria.
At the highest level, which is autonomous or driverless driving (Level 5), all restrictions are lifted. There are only passengers in the vehicle, none of whom have any driving responsibilities, while, at Levels 3 and 4 the users in the vehicle are only relieved of their driving duties temporarily. At Level 5, the occupants never have to drive the vehicle. The vehicle could also make a trip without any occupants at all as the car’s technology is able to handle all traffic situations completely by itself. The user simply selects their destination and can then be “chauffeured” there. They are just a passenger, like they would be if they were traveling by train or plane. At this level, the person behind the wheel is completely “out of the loop” and is no longer part of the human–machine control concept.