What’s behind the exciting new autonomous Level 2+?

Technology and Business

Alice Salter

Alice Salter



  • In this article, we review the levels of driverless capability and ask:

    • Why is the gap between Level 2 and Level 3 so significant?
    • What can be done to bridge that gap?
    • How might the introduction of Level 2+ prompt further development?

Not all autonomous vehicles (AVs) are made equal. That’s why, for some time now, the industry has accepted a six level system to categorise the capabilities of different driverless vehicles. These defined levels range from Level 0, a vehicle with no automation, through to Level 5, where all driving function is completely automated.


Generally, they act as a good guide for understanding driverless functions as well as a clear route for progress. Recently, however, developers have hit a bottleneck around Level 2 as many have achieved partial automation where steering and acceleration can be controlled by the vehicle, but a human driver must always be ready to take over. The gap between this and Level 3, where the human driver doesn’t need to constantly monitor progress, now looks wider than leaders in the field first thought.


Why is the gap between Level 2 and Level 3 so significant?


The difference between Level 2 and Level 3 automation essentially comes down to how engaged the human driver is required to be. Where in a Level 2 vehicle a driver plays quite an active role, at Level 3 they are able to be passive for the majority of their time in the vehicle. However, for this to work effectively, the vehicle must be aware of its own limits and be able to detect when to prompt the human driver to take over. That is quite a technological leap.


This is evidenced in the fact that though there are already a few Level 2 systems on the market, including Tesla’s so-called “Autopilot and Volvo’s Pilot Assist, Level 3 options are limited. Mercedes Benz’ latest S-Class provides an intriguing middle ground. Released with Level 2 capabilities, it can be updated over the air to achieve Level 3 in appropriate markets and can do the same again to reach Level 4 when legislation allows.


Honda recently launched one of the first ready-to-drive Level 3 vehicles, its flagship Legend model, in Japan. Equipped with a Traffic Jam Pilot system which controls acceleration, braking and steering under certain conditions, it allows drivers to switch off. Crucially, it can alert them to take back control. This is achieved through vibration on the driver’s seatbelt and, if they’re unresponsive, the system will perform an emergency stop. It will not just keep driving.


It is this action which is proving difficult for manufacturers to replicate. In order to keep users feeling safe and development moving forward, many have now put forward a case for Level 2+, where driverless capabilities improve, but drivers remain actively engaged, as in Level 2.


Image: Unsplash

How does level 2+ bridge that gap?


Level 2+ benefits manufacturers in that it allows a certain degree of freedom to continue developing automated functions without the pressure of making those functions work without human monitoring. There is no set definition here in the same way there is for the other well-established levels of self-driving functionality, but it’s broadly accepted that Level 2+ could be a middle ground where tech is pushed forward, but safety and trust is ensured by human intervention.


For technology company, Nvidia, for a vehicle to become Level 2+, it needs surround sensors for 360-degree perception, as well as deep neural networks running in parallel for robust object detection. This distinguishes Level 2+ AVs from those a step below which can operate with just forward-facing sensors, relying on drivers to pick up the rest.


It’s a useful distinction and demonstrates that an integrated combination of the most sought after self-driving features, like lane control, adaptive cruise control, traffic-sign reading, highway merging and more, could be delivered sooner than we might have thought.


What are the benefits of introducing this level?


The lack of driverless cars entering the mainstream has been something of a disappointment for AVs’ biggest fans in recent years. There’s no doubt that development has slowed in comparison to early predictions. Partly, that is due to the prohibitive costs which mean developing a vehicle of Level 3 or above would not be particularly profitable, but a lot of that is down to the technical difficulty of jumping from Level 2 to Level 3. Introducing a Level 2+ therefore might allow progress to speed up, or at the very least continue, in a way which is more achievable for developers.


Vitally, it will also make it significantly easier for OEMs to report their level of progress. Currently if a vehicle exceeds Level 2 but does not yet meet the requirements of Level 3, it would have to be classed as the former to avoid over-promising and under-delivering. This in itself creates false perceptions of stalled progress.


Interestingly, the introduction of Level 2+ might allow us to take a step forward not just with technical development, but also in terms of public perception and comfort with driverless technologies. As semi-autonomous systems become more common, it’s natural that drivers will gain more confidence with automated vehicle control, opening up the conversation for progress to levels where vehicles can take on more functions.



So, would the introduction of a Level 2+ categorization prompt further development? It certainly looks likely. And it looks likely too that this distinction would allow developers to better report progress and deliver Level 2+ vehicles to market. It could even help to build public trust and encourage continued research. It’s a yes from us.


What do you think? Will the introduction of Level 2+ have an impact? Or does the current six level system work? Is it important to keep re-assessing as the industry develops? Let us know your thoughts in the comments below.

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