DENSO ADAS / AD 安心できる、自動運転

#2Automation Levels

Automated driving is defined into five levels according to the extent of automated functions or the scenes supported.

(Driver Assistance)

Either acceleration & deceleration (longitudinal direction) or steering (lateral direction) of the vehicle is performed automatically. The operation may be limited depending on the places and/or the natural environment (Common up to Level 4).

(Partial Automation)

Both acceleration & deceleration (longitudinal direction) and steering (lateral direction) of the vehicle are performed automatically.

(Conditional Automation)

Both acceleration & deceleration (longitudinal direction) and steering (lateral direction) of the vehicle are performed automatically. Monitoring of driving environment and actions for safe operation are also automatically conducted by the system. However, the human driver has to respond to a takeover request from the system when the vehicle is unable to cope with the traffic situation.

(High Automation)

Both acceleration & deceleration (longitudinal direction) and steering (lateral direction) of the vehicle are performed automatically. Monitoring of driving environment and action for safe operation are also automatically conducted by the system. Even when the system is unable to cope with the traffic situation, it controls the vehicle as much as possible to mitigate the risk.

(Full Automation)

Both acceleration & deceleration (longitudinal direction) and steering (lateral direction) of the vehicle are performed automatically. Monitoring of driving environment and action for safe operation are also automatically conducted by the system. The automated operation isn’t limited depending on the places and/or the natural environment.

Automation 5 Levels

Level 1 isn’t included in the automated driving but defined as Driver Assistance.

Level 2 is designated as Partial Automation.

In Level 3, a wide range of functions are automated, with the expectation that the human driver will take over the driving task when the system is unable to cope with complicated traffic situations.


That’s why the human drivers has to be always ready to respond to a request to take over the driving task even though they are allowed to engage in a second task unrelated to driving operation while the vehicle is driving automatically.

We can call Level 4 as nearly full automation.

The vehicle drives automatically except for the case when extremely abnormal conditions occur or the vehicle itself fails.
The responsibility for driving lies in the vehicle, not in the human driver.

Level 5 refers to full automation. What we call unmanned driving falls into this level.

For the time being, vehicles with various automation levels with different functions will coexist in the market and in the road, and all of those vehicles call themselves as ‘automated vehicles’.

What is important for suppliers’ side such as automakers is to disseminate the definition and the functional limit of the automated vehicles to users in order to avoid dangerous situations and accidents that may arise due to usage beyond suppliers’ expectations.

For example, even though an automaker puts Level 2 label on their automated vehicle, if the user erroneously expects Level 4 automation from it, you can easily imagine that the possibility of traffic accidents goes up.

Automated driving that we all thought should bring convenience to us might become a very dangerous technology if the intensions of the provider and the user don’t match.

In order for us to use vehicles in the automated driving era correctly and safely, it isn’t enough to improve functions and performance alone.

What becomes more important than ever before is that, for automakers to have close communication with users, and, for users to understand product information correctly.