Autonomous driving explained
Technology and Business
What do we mean when we talk about driverless cars, self-driving cars or what some people call automated driving or autonomous driving?
Are we talking about vehicles that drive themselves, without a human on board? Or do we mean vehicles that merely take over some things that humans do now, like braking and steering?
Now, achieving a world in which fully autonomous driving is commonplace will not happen overnight. It will be a slow process, through which the cars gradually evolve to drive themselves piece-by-piece, with less-and-less need for human interaction. Therefore, we need different terms for the different levels of automation.
This is an overview of each of those
Five levels of autonomous driving
In 2014, the Society of Automotive Engineers (SAE) created six definitions that describe different levels of automation. As you can see from the table below, the SAE assigns a ‘zero’ to no automation, although most modern cars operate with a driver assistance system of some sort, making ‘zero’ unusual.
Level 5 means full automation (cars that drive themselves, without needing a driver on board). The other levels sit between these two extremes.
Unfortunately, not every institution agrees exactly with the SAE. The good news is that there is a lot of overlap between the definitions of all major automotive associations. The following table sets out the different levels of automation.
Our definitions of autonomous driving
At 2025AD, we use the following definitions:
- Level 4: “fully automated driving” (in certain driving scenarios)
- Level 5: “driverless”, “autonomous” or “self-driving”
We do this to distinguish whether or not a driver will be needed on board to intervene, or not.
Autonomous driving level 4 explained
We are sure level 4 is achievable by the year 2025 (hence our name). At level 4, the human driver can hand over full control to the vehicle in certain situations. For example, the driver could watch TV while cruising down the motorway without ‘driving’, because the vehicle is doing this itself.
However, at level 4, the human driver must be in the vehicle, ready to intervene should they need to. The human driver can also hit an ‘off-button’ at level 4 and drive manually.
Autonomous driving level 5 in explained
Level 5 vehicles drive themselves, without needing humans on board. Like most experts, we do not see this being achieved within the next 15 years. We know that some low-speed tests have taken place on private roads, but this does not mean it will happen on public roads soon.
Different terms for autonomous driving
Not everyone agrees with us. Some of our interview partners, guest authors, users and people quoted from other sources may define autonomous driving slightly differently from 2025AD. We aim to make this clear in all our articles.
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