Autonomous driving explained

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.

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.