How do self-driving cars navigate roads and traffic?

In the UK, trials of self-driving vehicles have been taking place since 2015 in Bristol, Coventry, Greenwich, and Milton Keynes, with British companies Wayve and Oxa spearheading significant breakthroughs in the technology.

Autonomous vehicles are currently not allowed to drive unsupervised on UK roads, with a human expected to remain in control of the car at all times. The Automated Vehicles Act became law in May 2024 and outlined the safety standards and procedures for autonomous vehicles. In June 2025, the government announced that businesses will be able to pilot small-scale ‘taxi- and bus-like’ services without a human safety driver for the first time from spring 2026, bringing this futuristic vision closer to everyday reality on England’s roads.

So, how do autonomous vehicles navigate their environment? The vehicles use numerous sensors to ‘see’ where they are going and detect potential hazards around the vehicle. These can include cameras, which identify traffic lights, road markings, pedestrians, and other vehicles; radar to measure the speed and distance of nearby objects; and LiDAR (light detection and ranging), which creates a 3D map of the surroundings using laser light. AI algorithms then process data from the sensors to make real-time decisions. This includes recognising objects, predicting the behaviour of other road users and determining the safest path forward. The vehicle’s computer-powered control system then translates AI decisions into actions, such as steering, braking and accelerating. Some vehicles also refer to high-definition maps and GPS to help determine their exact location and plan routes.

The combination of these technologies allows autonomous vehicles to operate with minimal or no human intervention, depending on their level of autonomy. There are six levels of automation for driverless cars. For example, Level 0 means the vehicle has no autonomous features; Level 2, which currently covers cars that are allowed to legally drive on UK roads, is where the car can take over some aspects of driving, such as automatic emergency braking, adaptive cruise control, and parking assist; and Level 5 means complete autonomy with no input from a human.

A significant benefit could be improved safety on the roads. Despite some technology failures during commercial driverless taxi pilots, statistically, autonomous vehicles remain safer than those with humans behind the wheel – they don’t get distracted and they stick rigidly to the rules of the road and speed limits. They may also increase efficiency by communicating with other autonomous vehicles to optimise routes and avoid traffic congestion.

The technology still has some catching up to do with human drivers in some situations, such as in poor weather conditions, complex traffic scenarios and in the face of unpredictable behaviour from pedestrians, other road users, and even passing animals. Legislation too, is needed to address liability, but as the technology improves and regulations adapt, we may soon see a future where cars drive themselves.