The six autonomous driving levels
Let’s look at each level in more detail:
Level 0 autonomous driving: no automation
As the name suggests, Level 0 relies completely on the driver to perform all longitudinal and lateral tasks, such as acceleration or steering. The driver is in complete control of – and responsible for – the act of driving.
While not featuring any form of automation, the system will give some warnings. These could be, for example, lane departure or forward collision warnings. As they only inform the driver through alerts and notifications, they still fall under Level 0.
Level 1 autonomous driving: driver assistance
At this level, the vehicle only controls or intervenes to control the speed or steering of the vehicle, but not both at the same time.
While the driver can’t relinquish control of the car, Level 1 systems assist with some driving tasks. An example of such an ADAS function is adaptive cruise control, where the car will keep a set speed and safe distance between the car ahead by automatically applying the brake when traffic slows and resuming its original speed when traffic clears.
Another use case is lane keep assist, which brings the car back into the middle of the lane in case the vehicle veers off slightly without activating the turn signal – yes, it sometimes happens even to the best of us!
Level 2 autonomous driving: partial driving automation
Moving up to Level 2, the driving task is shared between the vehicle and the driver. The vehicle usually takes over the two primary driving functions of lateral and longitudinal control. This can be achieved, for example, by combining adaptive cruise control with lane keeping. In this case, the driver is allowed to temporarily take their hands of the wheel. However, the driver still needs to have constant situational awareness and monitor the surrounding environment.
Some of the most notable examples of carmakers using Level 2 automation are GM’s Super Cruise, the Mercedes-Benz Drive Pilot, the Tesla Autopilot, Volvo’s Pilot Assist and the Nissan ProPilot Assist 2.0.
A new trend in the automotive industry is Level 2+ systems, which exceed the functionality you would typically find in a Level 2 model. The main difference between the two is a higher degree of automation when maneuvering to enter or exit a highway, change a lane or merge onto one. Taking the example of changing lanes, a Level 2 system would simply stay in the same lane, even when driving behind a very slow vehicle that it is allowed to overtake.
Level 3 autonomous driving: conditional driving automation
At Level 3, the vehicle can accelerate past a slow-moving vehicle, monitoring its surroundings, changing lanes, and controlling the steering, throttle, and braking. All the driver has to do is keep paying attention and be ready to take back control when the vehicle calls for it.
Level 3 automation allows you to take your hands off the wheel and eyes off the road – as long as you remain alert. The result is a relaxed driver on certain occasions, like when driving in traffic jams. Most car manufacturers allow such a traffic jam pilot function to operate only on specific controlled access highways and operate when traffic is relatively slow – below 40 miles per hour.
Level 4 autonomous driving: high driving automation
At Level 4, the interaction between human and machine (HM wheel. However, I) lowers as the vehicle’s capability increases. Steering, braking, accelerating and monitoring the environment are taken out of the driver’s hands, as well as changing lanes, turning and signaling.
The vehicle can handle highly complex driving situations, such as the sudden appearance of construction sites, without any driver intervention. At the moment, this is allowed for specific, predefined circumstances, such as on controlled access highways.
However, a human still has the option to manually override. For the driver, this means she can safely relax and even read a book, while the car responsibly and safely drives on the highway and, possibly, even on city roads. The car can still prompt the driver to take back control, but if it receives no response, the car is able to bring itself to a safe stop. An example of Level 4 autonomy is the Waymo test car.
Level 5 autonomous driving: full driving automation
Now we’re getting to the really good stuff: autonomous driving.
Level 5 autonomy requires zero human attention. There’s no need for a steering wheel, no need for brakes and no need for pedals. The autonomous vehicle controls all driving tasks under all conditions, including the monitoring of environment and identification of complex driving conditions like busy pedestrian crossings.
This also means that the vehicle can perform a combination of several tasks simultaneously, whether adaptive cruise control, traffic sign recognition, lane departure warning, emergency braking, pedestrian detection, collision avoidance, cross traffic alert, surround view, park assist, rear collision warning or park assistance.
ADAS: the benefits of Levels 1 and 2
Being able to perform lateral and longitudinal control is the first step for vehicle automation. Driver assistance optimizes fuel consumption and creates a safer, more comfortable driving experience.
This is done by adding an extra layer of sophistication to adaptive cruise control, which results in predictive powertrain control (PPC). PPC extends a car’s vision beyond the range of sensors and knows the road geometry ahead. As a result, it enables adjusting and shifting gears and speed automatically based on digital map data of the road.
For vehicles, whether cars or trucks, this means improved powertrain efficiency and less fuel consumption. In the case of electric vehicles, it leads to less battery drainage. However, there is also a comfort element, as PPC allows drivers to forget about shifting gears or having to brake abruptly – contributing to a relaxed and smooth ride.
How the ADAS Map powers Levels 1 and 2 of autonomous driving
The maps that help create this experience are called ADAS maps. The TomTom ADAS Map has been proven to achieve up to 5% fuel savings, can help car manufacturers achieve higher Euro NCAP ratings and is already in over one million SAE Level 1 and Level 2-enabled automated vehicles on the road today.