By Alex Nishimoto of Motor Trend
Chances are you don't think much about the safety systems in your vehicle. But if you ever need them, it might be beneficial to know what's available in new cars today — and what your specific car is equipped with. Below is a brief overview of the safety features available today, and the ones that might save our lives tomorrow.
Read: Anatomy of a car crash
Passive safety features are systems that activate at the moment of impact. Probably the best known examples of these are crumple zones, seat belts, and airbags, both of which have been around for decades but have evolved significantly since their introduction. The job of the seat belt is to prevent you from flying through the windshield or smashing your face and body into something hard when your vehicle comes to a sudden stop. Similarly, airbags inflate upon impact to provide a softer landing for your face and other sensitive body parts.
Driver and passenger airbags have been standard since the '90s, but today's cars have anywhere from four to more than 10 airbags onboard, each offering protection from a specific injury or crash-related hazard. Side-curtain airbags deploy across the windows to help prevent head injuries in side impacts and rollover incidents, while side torso airbags defend against injury to the abdominal and pelvic areas. Knee airbags, now standard in many cars, deploy below the dash to guard against leg injuries.
One new innovation we've seen on some Fords and Lincolns is the inflatable seat belt, which is intended to take off some of the stress applied to your body in a hard stop. GM now offers a front center airbag that deploys from the right side of the driver's seat to provide additional cushioning in a side impact and prevents front occupants from bumping heads. Modern seat belts use a three-point design with one strap placed across your lap and one crossing your chest to help distribute the force of a sudden stop more evenly. To spread out that force and further reduce injury, an inflatable seat belt increases its surface greatly area when it deploys.
Another passive safety feature you might not think about often is a car's body structure. Cars have crumple zones built into their bodies, which are meant to dissipate energy in a crash — energy that would otherwise be transmitted to the occupants. Your car's front and rear ends are meant to deform in a certain way to help absorb the force of an impact. A sturdy safety cell structure encircles the cabin, and is quite often comprised of high-strength steel alloys reinforcing the roof and pillars to protect you in a crash. After an accident, some cars offer a subscription-based service that can automatically notify first responders of your position, and the severity of the crash based on data from the car and info you give to an operator, who calls after you get into an accident.
While passive safety features generally aren't used until the moment of a crash, active safety features do their best to prevent a crash. This area has seen great advancement over the years, but there are a few old standbys that continue to keep us out of trouble. Antilock brake systems (ABS), as the name implies, help prevent your tires from locking up and skidding under hard braking. ABS does this by monitoring the speed of all four wheels with sensors, and momentarily releasing brake pressure to an individual wheel to keep it from locking.
Traction control is often a secondary function of ABS, reducing engine power and/or applying individual brakes to prevent a wheel from spinning. Stability control uses a different set of sensors, which monitor your vehicle's lateral movement, rate of rotation, steering angle, throttle position and more. If the vehicle isn't responding appropriately to the control inputs, the system can apply brakes to specific wheels and vary engine power as needed to make the car follow the intended path.
Many of today's cars are smart enough to sense more than just your wheels slipping, and are in fact aware of other vehicles and objects around you. Collision avoidance or mitigation systems rely on a number of sensors, usually including radar, cameras, lasers, and/or ultrasonic sensors, to determine what's going on outside your car. If the system thinks you're approaching an object too fast, your vehicle will warn you with an audible chime from the speakers, a flashing light at eye level, vibration of the seat or steering wheel, or a combination of the three.
If a simple warning doesn't provide enough of a safety net, some vehicles can intervene to help you avoid an accident. For example, some Fords will prime the brake system's hydraulic lines in preparation for a hard stop when you hit the brakes. Toyotas with the Pre-Collision system will prime the brakes and also tighten the seat belt pretensioners. Vehicles from Infiniti, Volvo, and Mercedes-Benz will even apply the brakes for you when so equipped.
Another active safety feature that watches out for vehicles around you is the blind spot monitoring system. As with forward collision warning, blind spot monitoring systems vary from brand to brand. Virtually all systems will show a warning light on the exterior mirror or pillar when an object is detected in your blind spot, and also beep at you if you try to signal into that lane. Likewise, lane departure warning systems can sense when you're drifting out of your lane, and depending on the vehicle, will either alert you or bring you back automatically.
Most systems will beep and flash lights in your face, but vehicles such as the Cadillac ATS and XTS will also vibrate your seat to further grab your attention. Certain Infiniti and Mercedes-Benz models can gently apply the brakes to bring you back into your lane, and modern electric-power-steering systems will be capable of such corrective steering action in the near future. The warnings are only triggered if you start to cross over the lines without signaling, so drivers who don't like to use their turn signals might want to turn this feature off.
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