Digital Explainer – What level are autonomous cars at?

There has been growing interest in autonomous vehicles for many years. In 2017 there was a prediction that 4 million driving jobs in the USA would be at risk. We have yet to see mass adoption, and here in the UK, the Government has yet to update a 19th-century law to allow any autonomous use of our roads and pavements , but  the Regulatory Innovation Office (RIO) is looking at it. There remains a position in Government to enable autonomous vehicles from 2027 and, whatever the pace of change, it seems certain that the future will include them. In this Keynote, our technology partners James Tumbridge and Robert Peake explain what we need to understand about them.

The 5 levels of autonomy

In 2014, the Society of Automotive Engineers, now called SAE International (a global professional association and standards organisation), published 6 levels of autonomy, but since 2018, people often refer to a revised 5-level scale.

SAE refined the definitions further in 2021. This approach is more widely now adopted, with even the motoring magazine Top Gear citing it in 2023. In partnership with the International Organization for Standardization (ISO), the latest version known as SAE J3016 is the starting place of understanding:

Level 0: No Driving Automation

Level 1: Driver Assistance – vehicle features a single automated system for driver assistance, such as cruise control. It is Level 1 because the driver monitors the other aspects of driving.

Level 2: Partial Driving Automation – an advanced assistance system that can control steering and accelerating/decelerating. The driver can take control of the car at any time. Tesla Autopilot and Cadillac (General Motors) Super Cruise systems are Level 2.

Level 3: Conditional Driving Automation – these vehicles have environmental detection systems and can make decisions, such as accelerating past a slow-moving vehicle. They still have human override, and a driver must remain ready to take the wheel. Audi (Volkswagen) had plans to provide the world’s first production Level 3 vehicle but abandoned them in 2025. It was planned that the A8 would use a lidar scanner with advanced sensor fusion and processing power; now it is assumed it will deliver Level 2 cars.

Level 4: High Driving Automation – Level 4 vehicles can intervene, and operate in self-driving mode. But they can only operate in controlled areas via geo fencing, aligned with legislation and infrastructure. Generally, that will be an urban environment and limited speed up to 30mph. Alphabet’s Waymo has a Level 4 self-driving taxi service where it had been testing driverless cars.

Level 5: Full Driving Automation – Level 5 vehicles do not require human attention and are fully automatic. They may not have steering wheels or acceleration/braking pedals as they are not required, enabling a radical re-design of the interior. Fully autonomous vehicles are not yet available to the general public.

What’s next for autonomous cars?

By 2030, Goldman Sachs estimates up to 10% of global new car sales could be Level 3 vehicles. Therefore, big changes are coming, and there are different ways for those to be achieved. Much of the choice technically is about the sensor system. Radar, ultrasound and lidar (laser detection and ranging) have all been tried. AI is also integral to the growing capabilities of the vehicle to appreciate its surroundings and options; the costs and capabilities have been challenging, though.

To date, Tesla has taken a different approach. Its vehicles use imaging and cameras, both on the vehicle and in the wider world, relying on AI to help build the picture and complete the manoeuvre. The importance of AI was confirmed on 28 July 2025 when it was announced that Tesla and Samsung had entered into a $16.5B agreement for the supply of AI chips to the automaker.

Legislation is also on its way; the UK has already passed the Automated Vehicles Act 2024 and there has been significant progress in the USA in various trials with localised rules and permissions. Autonomous vehicles are coming; the unknown question is, when will they reach Levels 4 and 5?

If you have questions or concerns about the use of technology in autonomous cars, please contact James Tumbridge and Robert Peake.