Image by Steinar Engeland


Juan Carlos Aguilera

The world of autonomous vehicles is flooded with acronyms such as DDT, ODD, OEDS, ADS, and I’ll start introducing those terms as applicable on the different posts. 


An Automated Driving System (ADS) is defined by the Society of Automotive Engineers (SAE) at its standard J3016 as the Hardware and Software that are collectively capable of performing the entire dynamic driving task (DDT) on a sustained basis. This definition will be applicable for driving automation levels 3,4 and 5.


The British Standard Institution ( BSI ) defines a DDT as a Real-Time operational and tactical functions required to operate a vehicle safely in on-road traffic. This means that is the group of actions that a vehicle could take in a continuous way to drive safely on the roads.


In other words, an autonomous vehicle will be a set of hardware and software that can make and take decisions on the roads, in a safe and sustained way. 


What are the Levels of driving automation?


The Levels of driving automation are a classification done by the SAE defined on the J3016 standard. There are 6 automation levels, that goes from Level 0 (No Automation) to Level 5 (Full Automation), 


Currently, there is absolutely no one who has a Level 5 vehicle, there are several companies that are working on Level 4 automation and some of the great manufacturers are between Level 2 and Level 3.


So what does each level means:


Levels 0 to 2 are levels that are driver support features, this means that the driver must be available at all times and take specific actions to maneuver the vehicle at all times.


Levels 3 to 5: Are automated driving features, this means that the driver on some of these levels will take action only if the vehicle request it and in some others is not going to be necessary at all. 

  • Level 0: There is no automation on the vehicle and the operator is fully responsible for the actions of the vehicle. 

  • Level 1: There is a specific task that the vehicle can do by itself like accelerating and braking or changing from one line to another.

  • Level 2: Is when the vehicle can autonomously take decisions on accelerating and braking as well as changing from one line to another.

  • Level 3:  The driver must be available at all times. The vehicle can drive by itself under very specific conditions best known as Operational Design Domain ( ODD ), but can request to the driver at any time to take control of it. 

  • Level 4: The vehicle can drive by itself on a specific ODD, it can take safe action on an unexpected behavior even if the operator does not respond to an intervention request.

  • Level 5: The vehicle can drive by itself under any conditions. 


So what is an ODD?


The SAE Defines ODD as Operating conditions under which a given driving automation system or feature thereof is specifically designed to function, including, but not limited to, environmental, geographical, and time-of-the-day restrictions, and/or the requisite presence or absence of a certain traffic or roadway characteristics.

The Operational Design Domain are the specific conditions under which a given vehicle is designed to function.


This is currently a very broad definition because those specific conditions are not strictly defined anywhere and up until now that will be something that each manufacturer can define based on what needs and restrictions they think are better applicable to their design.


There have been some efforts from organizations like BSI to better define this but there is no official standard that specifies it yet. 


Example of the BSI Top Level ODD attributes:


So what did we got from all these messy definitions and acronyms? 

In the end, everything is trying to create a specific way and a common language to talk about autonomous vehicles, as this is not meant to be a highly technical forum, I’ll try to keep it simple moving forward but I think it is important to talk the same language and understand what the industry is doing. 

We are just starting on the Full autonomy trip, there are quite a lot of things yet to discover and a lot of controversy on multiple topics. 

We will have the opportunity to go over some of them later on, but for now, I hope this has been a useful introduction to what is an autonomous vehicle.

See you in the next post to discuss the leading companies on autonomous vehicles. 


BSI DDT Definition link 

BSI PAS1883  link  

SAE J3016 link 

SAE Autonomy Driving Levels link