In this fact page we will cover:

  • What is a connected and autonomous vehicle?
  • What is connectivity?
  • What is autonomy (or automation)?
  • What benefits can connected and autonomous (or driverless) vehicles bring?
  • How close are we to seeing fully driverless cars on our roads?
Driverless cars remove human error, a factor in
9 in 10
crashes on UK roads

How could self-driving vehicles improve road safety?

Self-driving vehicles have the potential to reduce or even eliminate crashes where human error is a contributory factor. Yet research shows that many people are confused about the benefits.


What is a connected and autonomous vehicle?

Connected and autonomous vehicles (or CAVs) combine connectivity and automated technologies to assist or replace humans in the task of driving. This can be through a combination of advanced sensor technology; on-board and remote processing capabilities; GPS and telecommunications systems.

Watch the video below to learn more and see these technologies in action.

Watch 'Our future journeys: safer by design' for more information on connected and autonomous vehicles


What is connectivity in vehicles?

A connected vehicle is able to share information (or data) with other sources both inside and outside of the vehicle. This could be with other vehicles, with road infrastructure or with any other connected network or thing.

Connectivity can mean, for example, that a vehicle can ‘know’ another vehicle is approaching over the brow of a hill, even though it can’t ‘see’ it, and can ‘know’ there are roadworks around the corner. Connected technologies therefore have the advantage of being able to perceive things that are further away than sensor technology, however, they require a coordinated approach to enable all vehicles and infrastructures to communicate compatibly.

Connectivity can play an important role in road safety as well as traffic management, bringing benefits related to congestion, and, potentially, air quality. However, connectivity also poses challenges in relation to technology compatibility, data protection and cyber-security.


What is autonomy (or automation)?

Automated technologies are those which undertake parts of the driving task, or in the case of full autonomy, the whole driving task (hence the use of the term, 'driverless car'). Many automated safety technologies are already present on modern vehicles, such as Autonomous Emergency Braking (AEB).

SAE levels of automation
Source: Society of Automotive Engineers (SAE), Related to Driving Automation Systems for On-Road Motor Vehicles (SAE J3016)

What benefits can connected and autonomous (or driverless) vehicles bring?

Motor vehicles are the cause of most crashes, injuries and deaths on UK roads, as well as creating congestion which can pollute the air and make our streets less welcoming.

Connected and autonomous vehicles have the potential to eliminate human error from driving, a factor in nearly 9 in 10 crashes on UK roads, and assist traffic management, meaning that congestion and pollution is reduced.

Fully driverless vehicles also offer potential benefits for those with additional mobility needs, such as the elderly or disabled people.


How close are we to seeing fully driverless cars on our roads?

Opinion is split on how long it will be until we see fully driverless cars, in all road environments, on our roads. It is likely that advanced connected and autonomous vehicles will be rolled out in more closed and controlled road systems, such as on motorways, where there is greater consistency in the road environment. Other road types pose different, and likely more complex challenges. Urban roads are in densely populated areas with people walking, cycling and driving in close proximity, whilst rural roads often have inconsistent, or insufficent, road markings to work with certain sensors, as well as suffering from less robust network capability, reducing the ability for connected technologies to operate.

The government wants to see fully self-driving cars, without a human operator, on UK roads by 2021

Autumn Budget 2017, UK government


The HelmUK platooning project, is an example of a trial of connected and autonomous technologies on UK roads. This project is trialling technology that allows HGVs to travel safely in close proximity at speed with the driver of the lead vehicle controlling the speed, acceleration and braking of the whole ‘platoon’. However, it is important to note that platooning is still not driverless technology; all of the vehicles within an HGV platoon have a driver ready to take over manual control or leave or dissolve the platoon if necessary, at all times.