From 7 January 2027, manufacturers selling vehicles in Great Britain will only be allowed to use the phrase – and some other similar terms – if the vehicle has officially been recognised as capable of driving itself. The Automated Vehicles (Marketing Restrictions) Regulations 2026, laid before parliament in July, protects eight terms including ‘self-driving’, ‘driverless’, ‘automated driving’ and ‘autonomous driving’. ‘Automated’ and ‘autonomous’ will also be restricted when used to describe a vehicle as a whole or its overall driving capability.
“The industry has seen lots of terms,” says David Ward, head of functional safety at automotive testing specialist Horiba Mira. “Things like automated, autonomous, self-driving, also phrases like robotaxis and so on, all come to mind – and when people start to use terms like that, there often can be different expectations in people’s minds about what they mean.”
That makes the clarification welcome, Ward says, particularly because misunderstandings have consequences. “It’s very important that users of these vehicles understand what the technology is capable of – and also what its limitations are.”
Until now, engineers have commonly talked about driving automation using the SAE levels of automation, which run from Level 0 to Level 5. The government says those terms are still able to be used. But calling an unauthorised system ‘partial self-driving’ would be forbidden.
For engineers, that means ‘self-driving’ has become something more like safety testing than anything else.
“Companies developing a product or a system like this need to have a level of confidence or assurance in the technology,” Ward says. One fundamental issue is what he calls the “risk acceptance criteria”: exactly how safe does a vehicle have to be before engineers, manufacturers and eventually regulators are prepared to say it can replace the human at the wheel?
The government’s current draft statement of safety principles suggests automated vehicles should be the rough equivalent of a “careful and competent” human driver, as tested by obeying traffic laws and reacting to hazards. That is the sort of thing an engineer can work towards.
“Historically, regulation sets minimum requirements and often manufacturers will go further for their own due diligence and their own confidence in the product,” Ward says.
“The real-world situation is the key test for a lot of this. People like to criticise human drivers but actually human drivers are incredibly adaptable, and often if we’re faced with something that’s new or unusual, we’ll know what to do about it.”
The challenge is proving an automated system can cope with a sufficiently broad range of situations, including rare ones that developers tend not to account for in training data.
For engineers, the need is to properly define the operational design domain (ODD) – the conditions in which an automated driving system has been designed to work. That includes the types of roads, locations, speeds, traffic, weather or other constraints. The problem is each ODD can be drastically different, depending on the type of road and the conditions in which it operates.
“If it looks like a vehicle is going to go outside the ODD, how do you deal with that in a safe and predictable way?” asks Ward. If a car simply stopped whenever it came across an unknown issue, it would cause tailbacks and pile-ups.
The Automated Vehicles Act 2024 also requires car manufacturers and the engineers they employ to show that a vehicle’s safety is maintained throughout its life, not just before it rolls off the production line. Exactly how any ongoing authorisation and guarantee process will operate has not been agreed by the authorities, but it is likely to put more of an onus on how well a vehicle can collect data.
“I think the important thing is that people need to recognise that we’re all in this together,” Ward says. “Manufacturers, regulators – even people representing the voice of the users – ought to be talking to each other and having a common understanding.”
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