Electronic stability control (ESC), which selectively applies brakes to one or more wheels when a vehicle is about to slide out of control, is the most important safety advance since the safety belt. Recent studies have found that ESC could save as many as 10,000 lives a year if all cars had the system. Beginning in 2012, the federal government will require that all new cars come equipped with ESC.
On a smaller scale, backup cameras, another safety system that is becoming more common, can now help prevent accidents with children or objects hidden in a vehicle’s rear blind zone.
The industry has gone a long way to make cars that can protect passengers in a crash, so now the trend is toward creating technologies for crash prevention. This will dictate the types of new safety systems we will see in mainstream cars. Most of the following have already turned up in limited use and the others appear to be just over the horizon.
New ESC systems will go further in managing vehicle dynamics. One system, ESC II, is designed to provide slight steering input, together with selective braking and throttle reduction, to maintain control. Rear-wheel steering control through an active multilink suspension is also being looked at to work with next-generation ESC, providing optimum stability.
Usually mounted in a vehicle's headliner above the windows, curtain air bags deploy across the windows in a crash to protect passengers' heads in both front and rear seats. They also help shield occupants from flying debris, and can keep people from being ejected during a rollover. The better head-protection systems offer a safety-canopy system, which automatically deploys the side-curtain air bags if the system detects the vehicle beginning to roll over.
Currently found on a few vehicles from Mercedes-Benz and Lexus, these sense a collision before it happens and take action to warn the driver and maximize the safety of all the car’s occupants. It detects vehicles in front and can sound an alarm and display warning lights. The system then takes preventive steps such as fully charging the brakes and air bags, closing windows, adjusting seat positions for optimal air-bag effectiveness, and activating safety-belt pretensioners. An advanced pre-collision system in the Lexus LS600h L will detect pedestrians and animals on the road as well as other vehicles. And a camera will watch if the driver is not looking ahead at potential road hazards and sound an alert to get his attention if it senses an impending collision.
In addition to maintaining a set speed on the highway, this system can automatically maintain a safe distance from the vehicle ahead. It does this by using radar to monitor vehicles in front, and operates the brakes or throttle to slow or accelerate the car as needed. We tested adaptive cruise control in a few vehicles and some of our drivers found the systems to be annoyingly abrupt in their operation. By 2009, Volvo will have a system that works in stop-and-go traffic and will be able to bring a car to a complete stop if necessary.
Cameras that detect the stripes between lanes can determine if a sleepy or inattentive driver has let the vehicle wander off its intended path. The driver is then alerted with a chime and warning light. We tested a system on the Infiniti M35x and found that the chime went off constantly on minor roads. Many of our drivers found it so annoying they turned it off. It was more useful on the freeway.
This system senses when emergency braking is required by gauging how fast the pedal is depressed. When panic braking is detected, brake assist builds up boost to use the vehicle’s maximum braking capability even if the driver doesn’t push on the pedal hard enough, which might happen in some crash situations.
Many accidents occur when a driver tries to change lanes without being aware that a vehicle is in a blind spot. Audi and Volvo currently have systems that use warning lights connected to cameras or radar on the outside mirrors to tell a driver when a vehicle is in or approaching a blind zone.
These systems use infrared technology to allow a driver to see objects, animals, and people well beyond the reach of a car’s headlights. We’ve found them to be useful in some situations, but not ideal. New systems by BMW, Mercedes-Benz, and Lexus might provide a greater range. In the past, we found these systems to be distracting; we hope that the new ones will be less so.
Traction control helps keep two-wheel-drive vehicles moving in slippery conditions. If it detects a drive-wheel slipping, it automatically applies a slight amount of brake pressure to that wheel and, if necessary, cuts back on engine power to stop the slipping. Traction control can also send power to whichever drive wheel has the most grip. But if neither drive wheel has grip, traction control won't help. While ultimately not as good as all-wheel drive or four-wheel drive in extreme conditions, traction control may be all you need in light rain or snow. It is especially helpful on rear-wheel-drive vehicles.
Roll sensors augment stability control and determine if the vehicle is tipping up on two wheels. If an impending rollover is detected, stability control applies selective braking to suppress the roll motion. If that fails, curtain air bags are deployed and stay inflated for about six seconds to protect occupants from possible impact and to help keep them from being ejected.
This technology moves the restraints behind a person’s head forward during a collision to help absorb energy and prevent whiplash injuries. Neck injuries are the most common kind reported in auto crashes and tests have shown that good head restraints, especially active ones, are effective in preventing them.
These systems already exist in some higher-end vehicles, where you can use them to control the climate, audio, cell-phone, and navigation systems. Early versions were cumbersome to use and had difficulties recognizing voice commands, but the technology has made great strides. Some voice-recognition systems are now used with Bluetooth technology, which pairs up your cellular phone to the car’s audio system. Using voice commands instead of buttons, knobs, and touch screens should reduce driver distraction, which could in turn reduce accidents.
Offered on a few Volvo models, proximity warning systems alert inattentive drivers before they rear-end another car. Proximity warning systems are only available on cars equipped with adaptive cruise control, as they use the same radar. If you come up behind another car too quickly, the system sounds an alert and flashes a red light at the base of the windshield. If you still don't slow down, the Volvo system can apply the car's brakes to avoid or reduce an impact.
Cameras that send an image to a dashboard-mounted screen when you shift into reverse are becoming increasingly common. Available on many cars, trucks, and SUVs, these cameras add a measure of safety, particularly on larger vehicles with big blind spots. Consumer Reports testing has shown that for shorter drivers in some of the worst vehicles, a small child can't be seen when less than 70 feet from the rear bumper. Cameras show what's immediately behind the cars, which also makes them handy for hooking up a trailer. The downside is that cameras often come bundled with navigation systems, and they can add $2,000 or more to the sticker price.
Tires that can maintain their shape and can be driven on for 50 miles or more with no air in them are becoming increasingly common on some new vehicles. More than just a convenience item, run-flats can add a degree of security by eliminating the need to change a tire in bad weather or dangerous roadside areas. But their stiff sidewalls can deliver a harsher ride. And some owners have complained of premature wear and high replacement cost.
The combination of telecommunications and computing technology is becoming more common in new cars. The most common system is General Motors' OnStar system, which is now standard on many GM vehicles (it's a subscription service after an initial demonstration period.). Also, marketed by Lexus, OnStart allows drivers to speak with an operator in an emergency by simply pushing a button. If the vehicle sends a signal that it has been in an accident, an operator can call to check on you. A built-in microphone and the car's stereo speakers enable the motorist to speak with an operator. Other manufacturers including Mercedes-Benz and Acura have their own telematics systems.