How autonomous emergency braking in cars can save lives

A good example is Volvo’s version, which starts with the same laser as the Ford Focus. This lidar (light detection and ranging) keeps its beady eye out for slowing or stopped cars and works up to 19mph (30km/h), but in full spec it’s also linked to a camera and two radar sensors that’ll work at higher speed too.

Together they’ve been programmed to not only identify cars, but also pedestrians. And in the future Volvo says the system will recognise runaway animals too.

They’re not cheap to buy, for example to spec the emergency braking on the Focus costs £1,000 on the Zetec model, but it also comes bundled in with other safety equipment using the same sensors, including on the Focus a system whereby the camera will snap road signs to display the current speed limit on the dash.

Most commonly, however, they’re linked to the autonomous (or adaptive) cruise control. This radar system keeps a set distance to the car in front and has been around for over 10 years, with even high-spec versions of the Nissan Primera having it in 2002.

It was Honda who first had the confidence to say, right, we know this system can automatically brake the car, so let it emergency brake too. First sold in the UK with the CR-V SUV in 2006, it was described as brake mitigation, which meant it wouldn’t bring the car to complete stop. It was enough to dramatically reduce the size of the impact, but the now-awake driver was expected to supply the rest. It also introduced the now-common idea of preparing for a crash, here tensioning the seat belts.

The latest AEB technology will automatically brake to a stop if the series of warning alarms doesn’t alert the driver. Audi’s top-spec system, Pre-Sense Plus, features a camera in the rear of the car as well so it knows it’s safe to do a full-on emergency stop from any speed without risk of another car ploughing into the back.