Brake assist detects when a driver initiates a panic stop (as opposed to ordinary gradual stops) and applies the brakes to maximum force. In conjunction with anti-lock brakes, the system enables threshold braking without locking up the wheels. Studies have shown that most drivers, even in panic stops, don’t apply the brakes as hard as they could, so Brake Assist intervenes to reach the shortest possible stopping distance.
Adaptive cruise control
Adaptive cruise uses lasers or radar to keep a constant distance between you and the car ahead, automatically maintaining a safe following distance.
Forward-collision avoidance (aka, forward-collision warning or forward collision braking)
Forward-collision warning uses cameras, radar or laswer (or some combination thereof) to watch for cars ahead and alert the driver if they are approaching too fast or not paying attention. The systems alert the driver with some sort of visual or audible signal or both. Advanced forward-collision braking systems typically use Brake Assist to apply the brakes when an imminent collision is detected. Even basic forward-collision braking systems can stop a car quickly enough to avoid a collision at speed differentials up to 20 mph. At higher closing speeds, the system can’t stop the car in time, but will still apply the brakes to reduce the accident forces and prepare the cabin (seat belts, air bags) for impact.
Adaptive cruise control
Adaptive cruise uses lasers or radar, such as those used in forward-collision avoidance systems, to keep a constant distance between you and the car ahead, automatically maintaining a safe following distance. The most advanced systems can also accelerate the car after a stop at a traffic light or during a traffic jam, allowing the driver to do little more than watch and steer.
Using radar or cameras, this system illuminates a light or icon in or adjacent to the outside mirrors to warn that another vehicle is lurking in the lane beside, possibly hidden in your car's blind spot. Many systems also sound an audible warning if you attempt to move over anyway or operate your turn signal indicating that you’re going to. Also effective are outside mirrors with a small convex section for a wide-angle rearward view.
Lane departure warning (LDW)
This alerts you if your car drives out of its lane without the turn signals activated. Using a camera or lasers to monitor lane markers, the LDW may sound a chime, blink a dashboard telltale, and/or vibrate the steering wheel or seat. High-tech versions can even intervene, using your car’s stability-control system to help prevent you from sideswiping another car.
Volvo offers an optional pedestrian detection system that uses radar and cameras to detect people in front of the car. At speeds up to 22 mph, it automatically applies the brakes if the driver fails to react in time.
Active head restraints
Active head restraints move up and forward in a rear crash to cradle the head and absorb energy in an effort to mitigate whiplash injury.
Mostly used as a parking aid by providing a bumper-level view aft, a backup camera can also assist with spotting a child or pedestrian concealed in the blind zone immediately behind the vehicle. A recommended convenience, this is a safety feature whose value is made apparent every time you drive. (See our blind spot measurements on vehicles.)