How autonomous are autonomous cars?

SAE levels of automation

How autonomous are autonomous cars?

June 30, 2017
Daan de Geus

In the media, there is a lot of attention for autonomous cars and their potential benefits. However, it seems that not everyone has the same definition of an autonomous car. Are they supposed to drive without any human supervision? Should they be able to drive autonomously in all conditions? These are all fair questions, to which there is not a straightforward answer. It is, however, possible to make a distinction between different automated cars based on their automated driving capabilities, using the SAE levels of automation.

What are the SAE levels of automation?

The levels of automation are defined in the J3016 standard of the Society of Automotive Engineers (SAE). This is the standard by which the level of automation is judged in the automotive industry.

There are six levels in total, running from level 0 to level 5. The level of automation of a car is based on different conditions, such as being able to drive and steer in an automated fashion, and whether it is required for the driver to intervene if requested. An overview of all levels and conditions can be seen in the figure below.

It can be seen that, in the lowest level, the human driver does everything on its own. In level 1, there is some software that assists the driver, such as cruise control, in order to make the driving task easier. At level 2, the car already can both steer and accelerate by itself, in some driving modes. However, it is still required that the driver monitors the environment, so that he can intervene if necessary.

In level 3, the driver no longer has to monitor the environment, but it is expected that he responds appropriately to a request to intervene. One level higher, at level 4, this is no longer required. Here, the car can operate autonomously without human interaction, in some of the driving modes. Finally, in level 5, the car is fully automated, and the system can drive the car completely autonomously in all driving modes.

What SAE level do the automated cars of today have?

A lot of research is being done to level 5, and there are tests being carried out on public roads. Think about Google and Uber, for instance. However, these cars cannot be used by consumers yet.

The highest level that is being implemented at this time is level 2. This is being done by the Tesla Autopilot, for instance, which can currently drive automatically on highways. The system steers and accelerates/decelerates automatically, but it is still expected that the human driver responds appropriately to a request to intervene, and that a human monitors the environment. Furthermore, the Autopilot functionality does not function in all driving modes, as it is only possible to use it on the highway, for now.

What kind of automated vehicle is Amber developing, and why?

At this moment, we are working on the development of cars that can drive themselves in order to redistribute themselves across cities in which we have mobility hubs, without any humans being in the cars. When you look at the figure above, you can see that this car would belong to level 4. Since human intervention is no longer possible, because of the absence of a human in the car, we jump from level 3 to level 4.

However, we are not in level 5 yet, because we make the explicit choice to let the automated cars drive on designated roads, in calm traffic, during the nights. This means that the system is only applied in some driving modes. We explicitly choose to do so because this provides us with a nice use case, which can already be implemented very quickly.

Moreover, we will actually be the first to commercially apply self-driving cars of this level. This is possible because we do not attempt to directly start with a level 5 autonomous car, but one level below that. The fact that we start at level 4, however, makes it relatively easy for us to scale up to level 5, because we have already a real-time test case.

Want to know more about our self-driving plans? TechCrunch wrote a nice article about it.