Autonomous driving levels
Scale from level 0 (without automation) to level 5 (fully autonomous).

Which are the levels of autonomous vehicle?
More often we hear talk about autonomous vehicles and their possibilities and capabilities. But what really means autonomous vehicle? Are all autonomous vehicles the same?
No, not all autonomous vehicles are the same, since not all of them have the same capabilities. There are different levels of autonomous vehicles, based on what the vehicle can do for itself and what the human driver intervenes in.

The six levels of autonomous vehicles were originally defined by the Society of Automotive Engineers (SAE) International, an organization that sets engineering standards for various industries, including the automotive industry. The SAE defines the levels in a scale ranging from Level 0 (no automation) to Level 5 (fully autonomous).
However, it’s important to note that different countries and regions may have their own specific definitions and regulations for autonomous vehicles, and the SAE’s definitions are not necessarily the only ones that are used.
Autonomous driving levels
There are six levels of autonomous vehicles, ranging from Level 0 (no automation) to Level 5 (fully autonomous). Here is a breakdown of the different levels:
• Nivel 0
No automation. The driver is fully responsible for always controlling the vehicle.
• Nivel 1
Driver assistance. The vehicle can assist the driver with certain tasks, such as braking or steering, but the driver must always remain in control of the vehicle. They can control the vehicle longitudinally (accelerate or brake) or laterally, but never both the same time.
• Nivel 2
Partial automation. The vehicle can perform some tasks automatically, but the driver must remain attentive and be ready to take control of the vehicle if necessary. They can control the vehicle longitudinally (accelerate or brake) or laterally, and both at the same time. But the driver is always responsible for the vehicle and its behavior
• Nivel 2+
Not covered by SAE but is a de facto industry standard. Level 2+ is Level 2 where the driver is not forced to have their hands on the wheel. However, the driver remains fully responsible for the driving, and therefore cannot do any additional tasks. It is not autonomous driving, and the driver is always responsible. If there is no attention, the system will remind the driver to do so.
• Nivel 3
Conditional automation. The vehicle can perform all driving tasks under certain conditions, but the driver must be able to take control if the vehicle encounters a situation that it cannot handle. The driver could perform other activities while in the car, but this activity cannot prevent him from taking control of the vehicle in seconds if requested by the (vehicle) system and limited to an ODD. For example, he might read, check his cell phone, or watch a movie, but not sleep.
• Nivel 4
- High automation. The vehicle can perform all driving tasks under a wide range of conditions, and the driver can take their attention off the road. However, the driver must be able to take control of the vehicle if necessary. In Level 4 we can do everything the same as in Level 3, but now the user can completely divert their attention from driving. It could even sleep, within the parameters of the ODD.
• Nivel 5
Full automation. The vehicle can perform all driving tasks under any condition and the driver does not need to be present and not restricted to an ODD.

ODD: Operational Design Domain
Operational Design Domain. It is a series of factors that are determined for its operation. For example, a geographical area can be defined with a certain type of road at a certain speed, or according to the meteorological parameters. Describes the circumstances under which the vehicle can make use of the activated level of autonomy (at Level 3 or Level 4).
Reference source: https://www.sae.org/blog/sae-j3016-update