Levels of Automated Driving from L0 to L5 and Connected Cars

What are the levels of autonomous driving? The SAE scale has six levels. Level 0 has no automation, Level 1 adds a single aid such as cruise control, Level 2 steers and brakes while you watch, Level 3 drives itself in limited conditions, Level 4 needs no driver inside a defined area, and Level 5 drives anywhere with no steering wheel required.

by EV-Global Team on July 6, 2025

Few topics in cars attract as much hype, and as much confusion, as self-driving. Cut the buzzwords and it comes down to a clear scale: the six SAE levels of driving automation, L0 to L5. Each level hands a bit more of the driving from you to the car. This article explains what each car automation level actually allows, which cars sit where today, and gives a straight answer to the questions people actually search for: what level is Waymo, what level is Tesla, and what level is a Mercedes.

The short version: Tesla Autopilot and Full Self-Driving are Level 2, Mercedes Drive Pilot is Level 3, and Waymo runs at Level 4. We unpack what those numbers mean below. We also cover connected cars, because the higher levels lean on them.

One term you will see throughout is SAE, so it is worth defining first.

What is the SAE and SAE Levels of Automation?

The SAE (Society of Automotive Engineers) is the standards body that sets much of the technical rulebook for the automotive and aerospace industries. For autonomous driving, the SAE is best known for the SAE J3016 standard, which defines the six SAE levels of driving automation, from Level 0 (no automation) to Level 5 (full automation). Carmakers, regulators and the press all use these "SAE levels" so everyone is measuring the same thing. They are the reason a Level 3 car means the same on paper whether it comes from Stuttgart or California.

What are the Levels of Autonomous Driving? SAE Levels L0 to L5 Explained

What Are Connected Cars?

A connected car has a permanent internet link and can talk to systems outside itself: other vehicles, road infrastructure, and the manufacturer's cloud. It uses sensors, GPS and wireless links to share live data about its surroundings, such as traffic, road conditions and hazards ahead.

The umbrella term is Vehicle-to-Everything (V2X). A connected car can exchange data with other vehicles (V2V), with infrastructure such as traffic signals (V2I), and with pedestrians carrying a smartphone (V2P). The payoff is practical: earlier warning of hazards you cannot yet see, plus remote diagnostics and over-the-air software updates that let a car improve after you have bought it.

What Role Do Connected Cars Play in Autonomous Driving?

Connectivity is a foundational technology for autonomous vehicles. At Levels 3, 4 and 5, a car has to take in a large amount of data and decide what to do in real time. Talking to the world around it gives the car more to work with than its own sensors alone.

At Level 3, the Mercedes-Benz Drive Pilot still does most of its work with onboard sensors, but external data helps in the conditions it is built for, such as congested highways. When cars and roadside infrastructure share what they see, a vehicle can react to a jam or a hazard before its own cameras pick it up.

The higher you go, the more this matters. A Level 5 car would rely on its own sensors as well as data from other vehicles and from smart-city infrastructure. Low-latency networks such as 5G, paired with roadside sensors and the Internet of Things, are what make that kind of split-second coordination possible.

Comparison Table of Autonomous Driving Levels

Level	Degree of Automation	Human Involvement	Key Features
Level 0	No Automation	Driver controls all aspects of driving	Driver assistance features like warnings only
Level 1	Driver Assistance	Driver remains in control, assists with speed or steering	Features like cruise control or lane-keeping assist
Level 2	Partial Automation	Driver must monitor the environment and be ready to take control	Handles both steering and speed (e.g., Tesla Autopilot)
Level 3	Conditional Automation	Driver can disengage but must be ready to intervene	Vehicle can perform most driving tasks in specific conditions (e.g., Mercedes Drive Pilot)
Level 4	High Automation	No human intervention required in specific environments	Handles all driving tasks within a defined area, but can stop outside this area
Level 5	Full Automation	No human input required	Fully autonomous in all environments (future goal)

Level 0 (L0): No Automation

At Level 0 the human does all the driving. The car may warn you, but it never acts on the controls. A 2010s base-spec hatchback with nothing more than a lane-departure beep or a blind-spot light is Level 0: the alerts tell you something, but you steer, brake and accelerate yourself. Automatic emergency braking sits here too, because it only intervenes in an emergency rather than driving.

Level 1 (L1): Driver Assistance

At Level 1 the car takes over one task at a time, either speed or steering, but not both together. The driver stays fully in control. The classic example is adaptive cruise control, which holds your speed and gap to the car ahead while you keep steering. Lane-keeping assist on its own is also Level 1. You only leave Level 1 once a car does both jobs at once.

Level 2 (L2): Partial Automation

At Level 2 the car handles steering and speed at the same time, but you must watch the road the whole time and be ready to take over instantly. This is where almost every "self-driving" feature on sale today actually sits. Tesla Autopilot is Level 2, and so is Tesla's Full Self-Driving (FSD), despite the name: the driver is still legally responsible at all times. GM Super Cruise and Ford BlueCruise are Level 2 as well, even though they let you take your hands off the wheel on approved highways. So when people ask what level Tesla is, the answer for both Autopilot and FSD is Level 2.

Level 2 vs Level 3: where the responsibility shifts

The step from Level 2 to Level 3 is the one that matters most, because it is where legal responsibility moves from you to the car. At Level 2 you are always driving, even when your hands are off. At Level 3, inside the conditions the system allows, the car is driving and you may look away, but you must take back control within seconds when it asks. Everything below Level 3 watches you; from Level 3 up, the car watches the road.

Level 3 (L3): Conditional Automation

At Level 3 the car handles the full driving task, but only inside a narrow set of conditions, typically slow-moving highway traffic. Within that envelope you can take your eyes off the road; outside it, you drive. The Mercedes-Benz Drive Pilot is the standout example, and the answer to what level a Mercedes is: it was the first Level 3 system certified for public roads, first in Germany and then in Nevada and California, and it works in dense highway traffic up to about 95 km/h (60 mph). Drive Pilot is also the highest level of automation you can legally buy in a private car today.

Level 4 (L4): High Automation

At Level 4 the car drives itself with no one responsible behind the wheel, but only inside a mapped, approved area, its operational design domain. There is no need for a human to take over: if it hits something it cannot handle, such as bad weather or a road outside its zone, it pulls over and stops safely on its own. This is where Waymo sits, which answers another common question, what level is Waymo: Level 4. Waymo runs paid, fully driverless robotaxis with empty driver's seats in cities including Phoenix, San Francisco, Los Angeles and Austin. The catch is the boundary. Drive past the edge of the mapped zone and the car will not go.

Level 5 (L5): Full Automation

At Level 5 the car drives anywhere a human could, in any weather, with no steering wheel or pedals needed. There is no geographic boundary and no condition where it hands back to a person. No system on the road has reached this, and there is no car you can buy at Level 5. Most in the industry expect it to stay out of reach for many years; the hard part is not the easy 99 percent of driving but the rare, messy situations a human handles without thinking.

How do regulations affect autonomous driving?

The law decides what carmakers are actually allowed to switch on, which is why a feature can exist technically but stay locked in some markets. Germany was first to pass a Level 3 law and approve it on specific roads at limited speeds, which is why Mercedes launched Drive Pilot there. Japan and South Korea have followed with their own Level 3 rules. Above all of them, the UNECE writes the international standards that keep approvals broadly aligned across countries.

What is the future of autonomous vehicles?

Level 5 is the part that is still far off. The real near-term progress is at Levels 3 and 4: more carmakers are working towards Level 3 approval later this decade, and Level 4 robotaxi fleets keep expanding city by city. Connected cars and 5G are what let those higher levels work in dense, fast-changing traffic. The honest expectation is steady, level-by-level gains rather than a sudden jump to a car that drives itself everywhere.

The EV-Global verdict: the levels, and what they are good for

The SAE L0 to L5 scale is not perfect, but it gives everyone a common yardstick. It lets you compare like with like and cut through a carmaker marketing a Level 2 system under a name like "Full Self-Driving" (we are not naming names). The number on the box matters more than the word next to it, so it pays to know what connected cars and the rest of the stack actually do.

So, to put the levels next to the cars people ask about: Tesla Autopilot and FSD are Level 2, Mercedes Drive Pilot is Level 3 and the most you can buy, and Waymo runs Level 4 robotaxis on public roads. Level 5, a car that drives anywhere in any conditions, is still a long way off. The real change is happening one level at a time at L3 and L4, and that is where to watch.

Self-driving levels: frequently asked questions