There are several levels of autonomous driving, between a dystopian future of cars without steering wheels and the current reality where the driver is responsible for their vehicle. Here’s what autonomous driving is, what’s allowed and what distinguishes the different levels of autonomy.
Many vehicles available on the market today claim a certain level of autonomy. The naming of certain driving aids has in recent years contributed to the vagueness surrounding what autonomous vehicles correspond to. We think in particular of Tesla’s Autopilot, which can make us imagine a vehicle that drives its occupants, when this is not the case.
Legislation has had to evolve alongside technology to ensure roads do not become a playground for builders. At the same time, associations have proposed a standardized definition of the different levels of autonomy, so that we can navigate more easily.
What is autonomous driving?
Autonomous driving is in the collective unconscious what we have already observed in certain futuristic science fiction works: a car that drives “by itself”. However, the reality is not so simple, and there are several levels of autonomy which we will return to below.
Thus, the notion of autonomous car can designate both a semi-autonomous vehicle and a fully autonomous vehicle. In this case, manufacturers have not hesitated to maintain vagueness on these notions for a decade. For example, Peugeot in 2015 claimed to launch its autonomous cars in 2020, Renault-Nissan claimed to offer an autonomous car in traffic jams for 2016. At Tesla, the promise of the autonomous car is a common thread.
However, the reality for drivers is still a long way from 100% autonomous driving, no matter where they are on the planet. Some legislation may appear more lax than others, since the same car is not capable of the same maneuvers depending on its geolocation.
If you want to go further on the definition of autonomous driving, the associated Wikipedia page shows that it is a concept that is difficult to understand. In this case, many definitions are proposed, without one being more exact than the others. In France, a decree specifies the legal definitions for three levels of vehicles with driving delegation: partially, highly or fully automated.
Is autonomous driving authorized in France?
Definitions are included in legal texts in France, which necessarily imply certain authorizations relating to autonomous driving. Since the 2021 decree, several developments have taken place. We find, for example, notions of responsibility of the vehicle manufacturer (and no longer the driver or the holder of the registration certificate) when the automated driving system is in control.
As France is part of the European Union, the texts adopted at the European level are then adopted in France, like the developments proposed in June 2022 by the United Nations.
Thus, since summer 2022, level 3 autonomous driving has been authorized up to 130 km/h on roads with a central divider, and prohibited to pedestrians and cyclists. However, between authorization and availability in practice for all French people, there is a big difference. Especially since the majority of French people are wary of autonomous driving.
Some vehicles appear to have sufficient equipment to be used autonomously, and the legislation offers the possibility of using them. However, the transfer of responsibility to the manufacturer appears to be the reason for the absence of level 3, 4 or 5 autonomy on most cars today in France.
What are the levels of autonomous driving?
There are 6 levels of autonomy, classified from 0 to 5 according to the SAE (Society of Automotive Engineers, bringing together engineers, scientists and professionals from the automotive industry). They correspond, synthetically, on the one hand to a vehicle which offers no assistance to the driver, and on the other hand to a vehicle in which the driver performs no action, or is even absent.
Level 0: no active assistance
Although it is less and less present, level 0 does exist. These are essentially vehicles where all driving is delegated to the driver. The vehicle can warn the person behind the wheel using various visual or audible alerts, but it is the driver who makes all the decisions.
Level 1: only one driving aid
Almost all cars on sale today can be considered as level 1 autonomous. This is a single driving aid, which can be for example adaptive cruise control, or even parking assistance. keeping in the lane.
When we talk about level 1, there can only be one of these aids in operation, and not several simultaneously. Either way, the human being behind the wheel remains present, alert, and ready to take control 100% of the time.
Level 2: adaptive cruise control and lane keeping
The real gap in autonomous driving occurs from level 2. We find it on many new vehicles today, and the most popular version known to the general public of level 2 assistance is none other than Tesla’s Autopilot.
So, it is a combination of adaptive cruise control and active lane keeping. More simply, level 2 autonomy provides assistance with both steering and speed control.
This is again a level of autonomy in which the person behind the wheel is responsible for their vehicle in all circumstances, and must constantly monitor the automated driving functionalities. In addition, the driver must be ready, again, to regain control at any moment.
Level 3: the vehicle drives, not the driver, under certain conditions
If level 2 was still the responsibility of the driver, level 3 goes a step further. This is the level of autonomy from which, when the functionalities allow it, the person sitting in front of the steering wheel is no longer – in practice – the driver. It is the car that drives, and as long as the autonomous driving functionalities are activated, the responsibility is borne by the car. A level 3 autonomous system must therefore manage all aspects of driving: acceleration, braking, lane keeping, changing lanes, etc.
Since 2022, this level 3 autonomous driving has been authorized in France, without anyone really benefiting from it in practice. Mercedes’ Drive Pilot allows you to benefit from this level 3, in certain special circumstances (mainly in traffic jams on the motorway).
If level 3 allows autonomous driving, without human responsibility when engaged, it nevertheless differs from levels 4 and 5 in the sense that, when the vehicle requests it, you must take control again.
Level 4: true autonomy begins
Level 4 represents what we know best today. The gap between level 3 and level 4 is significant, since a level 4 autonomous driving system will not require the driver to take control of the vehicle when it is operating.
However, this is not autonomous driving in all circumstances. In fact, level 4 autonomy can once again only be activated under specific conditions. It can thus be a route preconfigured by the manufacturer, or a geographical area where level 4 autonomy is functional.
We can cite certain portions of the city, or certain urban areas where Cruise, Waymo and other autonomous taxis offer their services. It is not the person behind the wheel — if there is one — who is driving, but rather the vehicle that is driving the occupants. It is possible that the pedals and steering wheel will no longer be present on such vehicles, but we must ensure that the circumstances in which they will be required to drive are well managed by the autonomous driving system.
Level 5: 100% autonomous in all circumstances
The Holy Grail of autonomy is Level 5. A Level 5 system replaces a human driver in all possible circumstances. Thus, it is a level 4 generalized to all places on the globe, in all conditions.
For a system to be considered level 5, it must therefore be capable of transporting you on the highway at 130 km/h without any turns, as well as taking complex intersections with multiple priorities, while being able to give up the passage for emergency vehicles and other pedestrians.
We understand why, to date, there is no level 5 autonomous vehicle for the general public. The technology is probably not mature enough. The future will tell us if this will become possible, or if, on the contrary, it will only be a concept reserved for science fiction.
Finally, it is important to differentiate the capabilities of a vehicle from what we feel as a passenger: being driven from one point to another by a car is sometimes possible, but rarely in such a comfortable, serene and faster than with a human driver. What if the real challenge of the future was to offer exceptional level 2 or 3 autonomy, rather than a barely passable level 4 or 5?
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