Self-driving cars and buses: your guide to the future of autonomous vehicles

Vehicles that take care of themselves and the driver are the future, according to the government, which says: “Self-driving vehicles will make transport safer, more convenient and more accessible, improving the lives of millions of people.

“With 88 per cent of accidents currently involving human error, the potential for automated vehicles to reduce costs, injuries, and fatalities is enormous. They will empower people across the country to get around more easily, including to school or work which will boost productivity.”

The 2023 King’s Speech promised: “My ministers will introduce new legal frameworks to support the safe commercial development of emerging industries, such as self-driving vehicles”

But there are concerns about introducing autonomous vehicles on the roads of Britain. The new technology creates a range of risks: from motorists finding their skills have eroded to cyber-attacks with mass casualties. Here’s everything you need to know.

What is a self-driving vehicle?

A vehicle that travels for all or most of a journey without human intervention. “Self-driving vehicle” is largely synonymous with “autonomous vehicle” – though the latter term suggests a more advanced degree of automation.

There is a spectrum of autonomy from a bit of driver assistance (such as cruise control, which has been around for decades) to a fully self-driving vehicle that does not need or even allow human intervention.

The Society of Automotive Engineers has a range of levels to classify the degree of autonomy:

At present self-driving vehicles in the UK are largely limited to a bus shuttle across the Forth Road Bridge in Scotland and the Heathrow Pod, which connects Terminal 5 with a car park along a dedicated track.

The autonomous bus currently running across the Firth of Forth is Level 3. The Heathrow Pod is a sort-of Level 5, though it travels only on a segregated track with no other vehicles or pedestrians.

Cruise control would score a 1.

In April 2023 the government gave permission for Ford to activate its BlueCruise self-driving system on 2,300 miles of UK motorway – though the technology is currently only available on the 2023 Ford Mustang Mach-E, a pure electric vehicle costing upwards of £50,000. This is Level 2. Technologies such as Honda Sensing and Toyota Safety Sense are also Level 2.

Mercedes-Benz is expected soon to release the first Level 3 cars to drivers in California and Nevada.

Why do we want them?

According to ministers, “Connected and Automated Mobility” technology involving self-driving vehicles will lead to:

How do self-driving vehicles work?

Makers of self-driving vehicles deploy a range of technologies in anything from an adapted car, bus or truck to one designed from the drawing board not to have a human operator.

The normal manual inputs – to accelerate, brake and turn – are controlled by a central processor that uses some or all of these technologies:

The velocity of the vehicle relative to its surroundings and other users is assessed many times a second to allow the vehicle to determine the appropriate speed and direction.

Are they safe?

Yes, says the government: “Even at relatively low levels of automation, the technologies could reduce road collisions. At higher levels, it could significantly improve safety on our roads by markedly reducing human error.”

Ministers cite a claim from the Institute for Engineering and Technology that for every 10,000 errors made by drivers, a self-driving vehicle will commit just one.

With human error a factor in seven out of eight collisions on British roads, taking out the potential for error will boost safety.

The government says self-driving vehicles should be held to the same standard of behaviour as that expected of human drivers; competent and careful. “This standard is higher than that of the average human driver – which includes, for example, drivers who are fatigued, distracted or under the influence of drink or drugs.”

The test for vehicles will be that they can “drive themselves safely and can follow all road traffic rules without the need for a human to monitor or control the vehicle to maintain that level of safety”.

What could possibly go wrong?

Quite a lot. The most worrying threat according to the Transport Select Committee is of “a large cyber-terrorist attack targeting the operating systems of many self-driving vehicles simultaneously could cause mass casualties.”

Ashley Feldman, Transport and Smart Cities programme and policy manager at a trade body, Tech UK, set out several “significant” risks to the committee, saying: “Your steering, your braking, your acceleration and even the operation of the airbags … could be taken over by a malicious actor.”

Jesse Norman, minister for Decarbonisation and Technology, told the MPs: “In some respects it looks like it is inevitable, that there will be [cyberattacks] and that some of them will be successful.”

The MPs are also concerned about the with erosion of driver skills as motorists get used to the easy life. In many scenarios the driver will need to be on standby to take over the controls if the self-driving vehicle meets conditions for which it is not prepared.

The Transport Select Committee report says: “Greater automation will reduce time spent driving. Over time drivers may become less practised and therefore less skilled. Conversely, the demands on drivers will grow as they will be called upon to retake control of vehicles in challenging circumstances with little notice.”

So a self-driving vehicle may throw in the towel at any moment?

Potentially. The Highway Code says: “A self-driving vehicle’s ability to drive itself may be limited to certain situations or parts of a journey. Things like the type of road, time of day, weather, location and speed may affect this.

“While a self-driving vehicle is driving itself in a valid situation, you are not responsible for how it drives. You may turn your attention away from the road and you may also view content through the vehicle’s built-in infotainment apparatus.”

While a vehicle is in self-driving mode, the driver is not responsible for its actions – but may find control handed back abruptly, according to the code.

“If a self-driving vehicle needs to hand control back to the driver, it will give you enough warning to do this safely. You must always be able and ready to take control, and do it when the vehicle prompts you. For example, you should stay in the driving seat and stay awake. When you have taken back control or turned off the self-driving function, you are responsible for all aspects of driving.”

Professor Nick Reed from Reed Mobility told the committee of MPs: “The risk is that the driver is not ready to resume control and that control is handed back.

“I think we will need monitoring of the driver, or the occupant of the driving seat, to show that they are indeed ready and able to take over, and also that the vehicle is capable of managing the situation should the driver not be ready or able.”

What does the law say?

At the moment, not much – which is why an Automated Vehicles Bill is promised. The government says: “We need to update our laws to ensure the potential benefits of self-driving technologies can become a reality. The Automated Vehicles Bill puts safety and the protection of the user at the heart of our new regime and makes sure that only the driver – be it the vehicle or person – is accountable.”

In other words, if the vehicle is legally in charge, the person inside is not responsible for an accident.

“The Bill gives people immunity from prosecution when a self-driving vehicle is driving itself, given it does not make sense to then hold the person sat behind the wheel responsible.

“Non-driving responsibilities however will still remain with that person, such as maintaining appropriate insurance for the vehicle and ensuring proper loading.”

The firm that makes the self-driving vehicle will have clear responsibilities.

The government says: “Companies will have to meet safety requirements from the point a vehicle is introduced onto our roads or face new sanctions and penalties if they fail in their duty. These include fines, requirements to take corrective action, and suspension of operation.

“Criminal offences will apply in serious cases.

“Companies will have ongoing obligations to keep their vehicles safe and ensure that they continue to drive in accordance with British laws.”

When will all this come to a road near me?

The government believes: “By 2025, the UK will begin to see deployments of self-driving vehicles, improving ways in which people and goods are moved around the nation.

“By 2035, 40 per cent of new cars in the UK could have self-driving capabilities”.

Such predictions will require a huge improvement in 4G coverage, and driver take up, to become reality. The MPs on the Transport Select Committee are unconvinced.

Their report says: “Over the last decade, progress in this technology has failed to meet many of its promoters’ predictions, and this has bred understandable cynicism.

“Safety must remain the government’s overriding priority as self-driving vehicles encounter real-world complexity.”

The government says there will not be a big, sudden switchover, saying: “We are at the beginning of this journey, and human drivers will share the roads with self-driving vehicles for many years to come.”

Will I need to take another driving test?

Unlikely, though driving as we know it will certainly change. Becky Guy, road safety manager for England for the Royal Society for the Prevention of Accidents (RoSPA) told MPs on the committee: “The role of the driver effectively moves from operating the vehicle to becoming a system supervisor. The real challenge is keeping that person engaged and in the loop of the vehicle.”

The degree of attention required by the person nominally in charge of the vehicle will vary.

Steve Gooding, chief executive of the RAC Foundation, summed up the different degrees of driver involvement in an autonomous vehicle as “hands off, eyes off, nod off”.

“Hands off means that the vehicle will drive itself, but you need to keep alert,” he said. “Eyes off means that the vehicle will look after itself entirely. Nod off means that you can go to sleep and the vehicle will take you where you want to go.”