How effective are active safety systems and what does the future hold for them?
Active safety systems are now commonplace on cars.we explain why they’re so important and what the next developments will be Deaths on British roads fell by 44% between 2006 and 2016, down from 3172 to 1792
WHILE DRIVING AT 50mph, I deliberately steered the car towards the white line separating me from oncoming traffic. As I got close to the edge of my lane, the car gently steered itself back into the centre. I then changed tack and steered towards the grass verge, aiming to drive the car off the road, but as it neared the edge of the asphalt, the steering again corrected my error and guided the car back into its lane.
I then took my hands off the steering wheel completely and let the car steer itself along a straight stretch. For a short time, the car did exactly that, gently guiding itself away from the road’s edges whenever it veered off course. But then, even more cleverly, it sensed that I wasn’t steering, so it slowed down and stopped at the roadside, preventing a potential accident caused by driver drowsiness or sudden illness. (Don’t worry, I was doing all this on a test track, not a road.)
Automatic steering systems like that in the Volvo XC60 (our 2018 Safety Award winner) I was driving are the next big thing in car safety. And it’s easy to understand why: 17% of incidents in which people are killed or seriously injured in the UK are head-on or partial head-on collisions with other vehicles, while 15% involve a single vehicle leaving the carriageway or lane. In contrast, accidents in which a vehicle runs into the back of another account for just 6% . Not all new cars have such an extensive suite of active safety aids as the XC60, but there are some systems safety experts believe should be included on all new cars. These essentials are automatic emergency braking (AEB), blindspot detection and lane-keeping assist.
The simplest AEB systems monitor the traffic in front of a car. If traffic slows and you don’t, the system will sound a warning before automatically applying the brakes. In most cases, these systems can prevent a collision when a car is moving at up to 15mph and lessen the impact of crashes at up to 25mph. The benefit of this is clear, given that 75% of collisions happen at less than 25mph.
AEB is “probably the most significant development in car safety since the seatbelt”, according to Matthew Avery, head of research at Thatcham Research, the UK’S Euro NCAP testing organisation.
“It could save 1100 lives and prevent 122,860 casualties in the UK over the next 10 years,” he says. “Rather than protect the driver using the seatbelt and airbag, AEB aims to prevent the crash in the first place. That means less expense and hassle for drivers.”
That’s why, from the start of this year, Euro NCAP decided to make it impossible for any car to gain its maximum five-star rating if it’s not fitted with AEB as standard on every trim level.
Research by Euro NCAP has concluded that the fitment of AEB systems leads to a 38% reduction in rear-end collisions. The latest, most sophisticated systems are set to reduce this further because they can detect not only vehicles, but also other road users and pedestrians.
What’s the best AEB system?
There are four types of technology used on AEB systems: lidar, radar, camera and systems that combine radar and camera. Lidar sensors use light detection to work out how far away the vehicle in front is. They’re great at preventing low-speed crashes (below 15mph) but not so effective at higher speeds.
Road deaths rose for the rst time in six years in 2016, up to 1792 from 1732 in 2015. That equates to ve deaths per day
Radar sensors are more effective at longdistance vehicle detection. In general, they’ll help to prevent an impact when vehicles are moving at up to 30mph.
Camera-based systems can spot potential dangers and identify whether they’re a car or another road user, such as a pedestrian or cyclist. They get a 360deg view of the car and are also useful for parking and other low-speed manoeuvres.
Systems that use both radar and cameraderived information are the best of all, because they have long-distance detection and the ability to see potential obstacles nearby. This technology is standard on the XC60.
What’s blindspot detection?
Blindspot detection is a safety system that gives you a visual warning when there’s a vehicle in the blindspot on either side of your car. Some systems use cameras located in the door mirrors and others use radar, but all will illuminate a small, often flashing, light when there’s a concealed vehicle behind you. These systems are highly effective at reducing the number of blindspot-related accidents, which were on the rise in around 2010 due to the worsening rear and rear three-quarter visibility of new cars caused by thicker pillars, lower rooflines and smaller windows. Research in the US has concluded that when cars are fitted with blindspot detection systems, there’s a 23% reduction in the number of lane-change crashes resulting in injuries.
What’s lane-keeping assist?
Lane-keeping assist is important because it helps to mitigate high-speed head-on and partial head-on collisions, which result in a far higher percentage of deaths and serious injuries than low-speed shunts.
Two levels of the technology are available: systems that simply alert you if your car starts to veer into a different lane and ones that do so and then actively steer the car back onto the correct path. Lane departure alerts use cameras to identify lane markings and then send a visual signal to the driver, often shown on the dashboard, and a beeping sound when the car is unintentionally about to cross into another lane. Provided you indicate before making the manoeuvre, the system won’t activate.
The newer technology is lane-keeping assist, which steers the car back into its lane and slows it down if necessary after sending a warning that you’re heading onto the wrong side of the road. The steering input is subtle and is easy to override if required. Most systems also only work above 40mph so that they don’t annoy drivers in urban environments by reacting every time the car crosses onto the wrong side A fake car is used to see at what speeds a car’s AEB will work of narrow streets to get around parked cars.
What future safety technology is on the way?
The majority of the latest cars do a great job of protecting their occupants in a crash in terms of their structure and ability to absorb impacts – known as passive safety – as well as the fitment of seatbelts and airbags, so there’s less room for improvement when it comes to crash test standards. This has led safety experts to concentrate on advanced driver assistance systems that can prevent crashes from happening in the first place.
“It’s no longer about protecting occupants in an accident, but assessing how capable a car is of braking and steering automatically to avoid other vehicles, motorcyclists, cyclists and pedestrians,” says Thatcham chief executive Peter Shaw. He adds that Euro NCAP’S Roadmap 2025 plan “lays the foundation for safety assessment of future autonomous vehicles”.
This means that we can expect to see a range of improvements and enhancements to automatic steering and braking systems – technologies known as advanced driver assist systems. Other manufacturers are likely to follow Volvo’s lead and introduce systems that aim to prevent cars from being involved in headon collisions or running off the edge of the road by fitting an automatic steering function.
The next step on from this will be automatic emergency steering, which doesn’t gently steer a car back on course but takes over from the driver and reacts strongly to avoid an impending impact. Just as AEB stops the car if a crash is imminent, automatic emergency steering will steer the car out of trouble and then slow it down.
To encourage all car makers to follow the lead of those at the forefront of safety technology development, from 2020, Euro NCAP’S overall ratings will include a score for each new model’s lane-keeping assist system.
From 2022, Euro NCAP will begin testing cars’ automatic emergency steering functions, with a view to this becoming mandatory for a five-star rating soon afterwards.
Another focus will be on the ability of a car to detect and avoid collisions with a range of other road users. Presently, only the most sophisticated systems can identify pedestrians
Euro NCAP released its rst results in February 1997; a one-star rating for the Rover 100 resulted in the car being withdrawn from sale soon afterwards Anti-lock brakes became a legal requirement on all new cars in 2004 ‘The majority of the latest cars do a great job of protecting their occupants in a crash’
and cyclists, but a wider uptake of that technology will be encouraged in a bid to reduce the 23% of deaths and serious injuries involving these vulnerable road users. AEB will also be used to prevent accidents in other situations, such as when cars are pulling out of road junctions or reversing out of parking spaces.
In order to test these ever-evolving systems, Euro NCAP is continually adding new equipment to its crash testing armoury. Thatcham recently developed the Guided Soft Target, a fake car that’s solid enough to fool a driver assistance system into believing it’s another vehicle but won’t harm it if the system fails to react quickly enough to avoid an impact. There are also dummy pedestrians that can be timed to walk or run out in front of a moving car to test its pedestrian-detecting AEB. And alongside the current bicycleriding dummy, there are plans to introduce a motorbike-riding one to test systems that aim to prevent collisions with motorcyclists.
‘Automatic emergency steering will react strongly to avoid an impact’
What about monitoring drivers?
Manufacturers are also introducing and improving their driver monitoring systems. These also aim to address the high percentage of accidents that are caused by driver error by spotting when a driver is inattentive, distracted or too tired to drive. And in our ageing society, there’s growing concern over people suffering medical emergencies while driving. So, although this means that some time soon your car will notice if you’re not paying enough attention while driving and reprimand you, this technology will be a significant building block towards creating the safe self-driving cars of the future.
Wearing a seatbelt in the front seats became mandatory in 1983, although rear seat passengers didn’t have to wear them until 1987
AEB systems identify other vehicles using lidar, radar and cameras
Dummy cars, cyclists and pedestrians test AEB; in the future, they’ll test automatic emergency steering, too