Guide to safety features

The most important thing you can do to protect your life is to buckle your seatbelt. Safety belts save lives on their own, but many of the more advanced safety features, such as seatbelt pretensioners and air bags, work best for people who are buckled up to start with.

Don't overlook safety features when comparing different models. Antilock brakes and electronic stability control, for instance, are very desirable. Although now standard on new cars, these features are well worth seeking out if you’re buying an older car.

Here's a rundown of some of the more important safety gear.

Front air bags have been standard on all new cars since 1998 and light trucks since 1999. Most vehicles had them even before then. Crash sensors connected to an onboard computer detect a frontal collision and trigger the bags. The bags inflate in a few milliseconds—the blink of an eye—then immediately start deflating.

While air bags have saved thousands of lives, they also have the potential to cause injury or even death to children or to occupants who aren’t using a seatbelt. Children under 12 should be seated in the rear in an appropriate restraint system and rear-facing child seats should never be installed in front seats equipped with air bags.

Adaptive, or dual-stage front air bags, introduced in 2003, became standard across the board by the 2007 model year. Most air-bag systems now detect the presence, weight, and seat position for the driver and front passenger, and deactivate or de-power front air bags as appropriate to minimize the chance of injury to drivers positioned close to the wheel, out-of-position occupants or children.

Side air bags. Torso protecting side-impact air bags for front-seat passengers are also nearly universal, and some automakers offer side bags for rear-seat passengers, as well. Side air bags are fairly small cushions that pop out of the door trim or the side of the seatback. They help protect the torso, but most aren’t effective in protecting the head. Nearly all new models today also include additional “side curtain” bags that deploy from above the windows and cover both front and rear side windows to prevent occupants from hitting their heads and to shield them from flying debris. A curtain bag often also stays ‘inflated’ longer in most cases to also keep people from being ejected during a rollover or a high-speed side crash. The better head-protection systems deploy the side-curtain bags if the system detects that the vehicle is beginning to roll over. (For more information on crash testing and Ratings, see our Crash test 101 report)

Before antilock brakes came along, it was all too easy to lock up the wheels (stop them from turning) during hard braking. Sliding the front tires makes it impossible to steer, particularly on slippery surfaces. ABS prevents this from happening by using sensors at each wheel and a computer that maximizes braking action at each individual wheel to prevent lock-up. ABS allows the driver to retain steering control while braking, so that the car can be maneuvered around an obstacle, if necessary. Some drivers, unaccustomed to ABS actuation, may be alarmed as the pulsing sensation conveyed through the brake pedal and chattering at the wheels when used. Not to worry. This is the system rapidly applying the brakes to provide maximum power and control. The trick is to push hard on the pedal and let the system do its job.

This electronically controlled system limits wheel spin during acceleration so that the drive wheels have maximum traction. It’s particularly useful when starting off in wet or icy conditions, and/or launching with a high-horsepower engine. Some traction-control systems operate only at low speeds, while others work at all speeds.

Most traction-control systems use the car’s antilock brake system to momentarily brake a spinning wheel. This routes power to the opposite drive wheel. Some systems also may throttle back the engine, and upshift the transmission, to prevent wheel spin.

Electronic stability control (ESC) takes traction control a step further. This system helps keep the vehicle on its intended path during a turn, to avoid sliding or skidding. It uses a computer linked to a series of sensors—detecting wheel speed, steering angle, sideways motion, and yaw (rotation). If the car drifts outside the driver’s intended path, the stability-control system momentarily brakes one or more wheels and, depending on the system, reduces engine power to pull the car back on course.

ESC is especially helpful with tall, top-heavy vehicles like sport-utilities and pickups, where it can also help keep the vehicle out of situations where it could roll over.

Electronic stability control became standard equipment on all cars with the 2012 model year. It started on luxury cars years ago and then migrated to other vehicles. It became especially commonplace on SUVs. Automakers each tend to have a proprietary name for their stability control systems, as listed below. If in doubt whether a used car has it, find out before you buy. Prior to 2012, while a model may be available with ESC, not necessarily every trim or individual car was so equipped.

Consumer Reports’ auto experts highly recommend stability control, a proven life saver. Even with this and other safety systems, remember that the basic laws of physics still apply. Take any corner too fast, and you could push the vehicle beyond the system’s limits. So don’t just speed into a curve and expect the system to bail you out.

While the seatbelt is arguably the single most important piece of safety equipment, enhanced features help seatbelts do their job more effectively.

Seatbelt pretensioners instantly retract the belts to take up slack during a frontal impact. This also helps position occupants properly to take full advantage of a deploying air bag. Force limiters, a companion feature to pretensioners, manage the force that the shoulder belt builds up on the occupant's chest. After the pretensioners tighten it, force limiters let the belt play back out a little to reduce the force.

Some models offer inflatable safety belts in the rear seat that further reduce the force of the belts themselves on rear passengers in an accident and spread those forces over a wider area—a particular concern with more fragile occupants, such as kids or the elderly.

Adjustable upper anchors for the shoulder belts can make a meaningful safety difference. Adjustable anchors help position the belt across the chest instead of the neck to prevent neck injuries. They also can help keep the belt from pulling down on a tall person's shoulder, making it more comfortable and thereby encouraging its use.

LATCH (Lower Anchors and Tethers for Children)

All vehicles are now required to have the LATCH system to make child-seat installation easier and more secure. The system features built-in lower anchors and top-tether attachment points for LATCH-compatible child safety seats. The LATCH system was designed to encourage the use of child restraints by simplifying installation and eliminating challenges and incompatibilities that safety-belt installation may present. But we’ve found a number of cars and trucks in which the LATCH system is tough to use correctly, so try installing a seat before you buy a new child seat. Check our findings in the road test for guidance on fit and compatibility.

Brake assist

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 laser (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.  Some vehicles equipped with lane keeping assist will also allow the car to stay within the lane markings.

Blind-spot warning

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.

Pedestrian safety

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.

Backup camera

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 previous vehicles not equipped with a camera.)

Underinflated tires can hurt handling and fuel economy. They can even lead to a blowout as underinflated tires are more susceptible to damage and wear. A tire can lose air through the rubber and does so slowly so that many drivers don’t notice. A government regulation requires all vehicles made after October 31, 2006, to have a low-tire-pressure warning system. The type of tire-pressure monitor we favor measures tire pressure directly. Others gauge air loss indirectly by using sensors to count wheel revolutions. In either case, we still recommend checking your tire’s inflations pressure monthly with a conventional tire-pressure gauge.

Combining cellular telephone and Global Positioning Satellite (GPS) technology, several major automakers are offering an automated service that provides a high level of security and convenience. GM was the first to offer a factory-installed telematics solution with its OnStar service. Later systems include BMW Assist, Hyundai Bluelink, Kia UVO, Lexus Safety Connect, Mercedes-Benz’s mBrace, and Toyota Safety Connect. These systems allow the driver to communicate with a central dispatch center at the touch of a button. This center knows the location of the vehicle and can provide route directions or emergency aid on request. If an air bag deploys, the system automatically notifies the dispatch center, locates the vehicle, and summons emergency service, if the driver does not respond to a phone-based inquiry. A phone call to the dispatch center can find a “lost” car in a parking lot by beeping the horn, or unlock the doors if the keys have been locked inside or misplaced.

The cost of telematics systems are built into the price of most vehicles that have them, but a monthly subscription fee, typically $10 to $20, is usually required.

Most new, name-brand portable navigation devices include emergency assist features that can identify nearby emergency services.

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