The Cult of Cars, Racing and Everything That Moves You.
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What's A 'Level 4' Autonomous Car? This Chart Explains Everything

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Autonomous cars are coming, and while it may sometimes feel like they’re already here, they’re really not. It can still be confusing, since every manufacturer with anything remotely like an autonomous vehicle seems to overstate what the cars can do. Luckily, levels of autonomy have been decided, and knowing them can help. That’s why we made some charts.


Self-driving, autonomous, autopilot—these are all pretty vague terms. Autonomy in cars isn’t an on/off state, it’s more of a continuum, with a blending of the human and the machine over control of the car. To make matters worse, news reports and automakers often refer to cars as “Level 2" autonomous or one day achieving “Level 4" autonomy.

There’s actually two main systems of classification: the National Highway Safety Administration (NHTSA) divides the continuum of autonomy into five levels, while the Society of Automotive Engineers (SAE) divides them into six.


They’re generally fairly similar, and the best-known car currently for sale with an appreciable level of autonomy, the Tesla Model S’ Autopilot, happens to fall on the same level in both scales, Level 2.

We still have a ways to go before we get to full autonomy, and we’re already starting to see the consequences of overestimating just how independent these robot drivers really are.

So, I hope these charts can help you think about how much driving your robo-car is capable of, and help you make safe decisions when you’re deciding if it’s okay to try playing dashboard Jenga instead of watching the road.

Have some charts. First, here’s the NHTSA’s:


… and here’s how the SAE sees it: