Vehicle Safety Systems
The latest vehicle-safety systems may help you avoid a crash.
Modern cars have crumple zones, airbags, seatbelt pretensioners and whiplash-reducing headrests. They’re commonplace to help disperse crash energy and minimise or eliminate injuries in serious crashes, something that has been instrumental in slashing the national road toll by more than half over the past 30 years.
But in the past decade the focus has turned to avoiding crashes, by fitting so-called active safety systems. While some active safety features have been around for a while, with anti-lock brakes (ABS) and electronic stability control (ESC) helping control skids and slides, the latest systems use cameras and radars that can react faster and more reliably than the driver.
This acronym denotes autonomous emergency braking, which will automatically slam on the brakes when the system detects another object ahead. AEB is common now on mainstream models, although the systems can vary enormously. The more sophisticated AEB systems see through fog and rain to more accurately interpret everything from other vehicles to pedestrians and cyclists.
A vehicle might contain one or more of these types of AEB systems:
• Low speed: This version targets city driving where crashes often occur at low speeds but can cause debilitating injuries such as whiplash. These systems use cameras or lasers to look for the reflectivity of other vehicles and are not as sensitive to pedestrians or roadside objects.
• High speed: These systems utilise long-range radar to scan further ahead of the vehicle (up to 200 metres) at higher speeds.
• Pedestrian systems: These versions typically use a camera combined with radar to detect pedestrians by their shape and characteristics. The way pedestrians move relative to the path of the vehicle is calculated to determine whether they are in danger of being struck.
• Reversing AEB: A more recent development, reversing AEB is designed to brake the vehicle when it is about to strike an object while reversing. This includes pedestrians as well as inanimate items.
While modern cars have improved in almost every area, vision is one area where they have gone backwards, as more fashionable designs and safer structures conspire to obscure the driver’s view. Technology has come to the rescue, though, with sensors positioned in the mirrors or bumpers on the lookout for vehicles outside the driver’s view. A warning light in or near the exterior mirrors as well as audible warnings will alert you to any potential issues. More advanced systems can provide mild steering assistance to reduce the chances of an impact. Manufacturers are even developing these systems to look out for cyclists when the car is stationary.
Rear cross-traffic alert
Great for reversing out of driveways or parallel parking spots, rear cross-traffic alert uses rear radars to monitor traffic approaching from either side. Warnings are usually flashed up on the infotainment screen with an audible warning to alert you to approaching vehicles. Many rear cross-traffic alert systems will also apply the brakes to stop the car from continuing on its crash course.
Active cruise control
Cars that maintain a set speed have been around since the 1950s, but newer active cruise control systems use a radar to maintain a set distance to the car in front. The distance can be adjusted between various levels.
A forward-facing camera or laser sensor monitors lane markings to determine when the car is wandering out of its lane. Warnings will typically involve beeps or vibrations of the steering wheel or seat, encouraging the driver to take corrective action.
An extension of lane-departure warning, steering-assist systems provide gentle steering assistance to help keep the car in its lane. At the very least they can help reduce fatigue by assisting with physical driving duties and, more seriously, they can prevent the car running off the road. However, steering assist systems aren’t perfect so it’s imperative the driver still focuses and controls the vehicle.
The difference between having a crash and avoiding one can often be a few metres, which is the sort of distance brake-assist systems can knock off an emergency braking situation. The car’s computer monitors pedal movements to predict a potential emergency. Usually it involves a very quick movement from the throttle to brake pedal, something hard to replicate without an emergency reaction. As soon as you touch the brake having jumped off the accelerator the car almost instantly brings the brake system up to its maximum level, providing maximum braking almost instantly.
SOURCE: RACV – Author Toby Hagon