Auto safety has evolved from seatbelts and airbags that cradle and cushion the body in an accident to telematics systems that provide automatic crash notification and send help right away. But while many auto safety features help during and after an accident, more carmakers are now offering safety technology that intervenes before a crash to help minimize occupant injury and damage to a vehicle — or even avoid an accident altogether.
Through the use of sensors, cameras and onboard computers, these crash prevention systems warn the driver of a potential accident, better prepare the car and occupants for a collision and, in some cases, automatically apply the brakes if the driver doesn't act in time to avoid a crash.
While these systems are not a substitute for attentive and careful driving, they can make a substantial difference in the degree of injury to everyone and every vehicle involved in a car accident. They can also help you avoid a crash altogether, ushering in the next evolution in auto safety.
Though the technology first appeared on luxury cars, crash prevention systems have started to trickle down to more reasonably priced vehicles. Examples include the Adaptive Cruise Control and Collision Warning with Brake Support available on the 2010 Ford Taurus and the City Safety feature on the 2010 Volvo XC60. Below is a survey of crash prevention systems that are currently available, listed according to the automakers that offer them.
Acura
The Collision Mitigation Braking System (CMBS) that's available on the Acura RL, MDX and the new ZDX uses a radar sensor in the front grille that detects objects traveling ahead and monitors their distance and closing speed. When the system determines that a collision is possible, it warns the driver with a display in the instrument panel and an audible indicator.
If the driver doesn't slow down, the system tugs at the seatbelt and lightly engages the brakes, and if it determines that a crash is imminent, it cinches the seatbelts and applies brakeforce to mitigate impact velocity and the force of the collision. CMBS works in conjunction with adaptive cruise control, and both features are part of the Technology package option on the RL and the Advance package on the MDX and ZDX.
BMW
The 2009 BMW 5 Series offers Active Cruise Control (ACC) with Stop & Go that will completely stop the car in stop-and-go traffic while cruise is engaged, and automatically speed it up when traffic starts moving again. The feature is also available on 2009 7 Series vehicles, along with a collision warning system (CWS) that uses the ACC's radar sensor to detect whether a driver is in danger of colliding with the vehicle in front. A warning appears in the instrument panel as well as in the vehicle's optional head-up display.
If the driver doesn't slow the car in time, warnings flash and an alarm sounds and the brakes are prepared for an emergency. CWS is active even if ACC is turned off, and it has two sensitivity settings: one that issues more warning and one that issues less.
Ford
Adaptive cruise control and Collision Warning with Brake Support (CWBS) is available on the 2010 Ford Taurus, Lincoln MKS and Lincoln MKT. CWBS uses the ACC system's radar sensor to watch for vehicles ahead. If it senses a possible collision, the system warns the driver via a visual indicator projected on the windshield and audible warnings through the stereo system's speakers. It also pre-charges the brakes and activates electronic brake assist to help the driver stop more quickly.
Infiniti
Infiniti's Intelligent Brake Assist with Forward Collision Warning alerts a driver to a potential collision with audible and visual warnings and automatically engages the brakes to reduce collision speed and help mitigate damage in an accident. But instead of radar, it uses a laser range finder.
Intelligent Brake Assist with Forward Collision Warning is available on Infiniti's EX and FX crossovers, which also offer lane departure prevention to guide the vehicle back into its lane when the driver inadvertently drifts out of it.
Lexus
The Pre-Collision System (PCS) from Lexus debuted on the range-topping LS 460 and has since spread to all of the carmaker's sedans. It uses a radar sensor to gauge the distance and closing speeds of vehicles ahead. If the system's computer predicts that a collision is unavoidable, the front seatbelts are tightened and PCS prepares the brake assist feature so that increased brake pressure is available the moment the driver presses the pedal.
The Lexus LS 600h L hybrid also has an option called Advanced Pre-Collision System (APCS), which adds a driver attention monitor. An infrared camera mounted on the steering column senses if a driver is looking away from the road when an object ahead of the car is detected. If so, it sounds a beep and briefly applies the brakes to warn the driver.
Mercedes-Benz
Mercedes-Benz offers its Distronic Plus with PreSafe Brake system on all 2010 E-Class models as part of the Driver Assistance package. The feature is also an option on S550, S550 4MATIC, S400 Hybrid and S63 AMG models, and standard on the S600 and S65 AMG. PreSafe Brake works in conjunction with Distronic Plus adaptive cruise control so that if a vehicle in front of the host car slows down enough to possibly cause a collision, audible and visual warnings are issued.
If the system determines that the closing speed is too high to avoid an accident, it employs up to 40 percent of total braking force and prepares to apply full braking power once the driver pushes the pedal. If the brake pedal still isn't pushed within what the system calculates as 0.6 second before impact, PreSafe Brake will bring the full braking force to bear in an effort to stop the car prior to a collision.
Volvo
Available on the 2010 Volvo S80, V70, XC60 and XC70, Adaptive Cruise Control and Collision Warning with Auto Brake uses radar and a camera to detect vehicles up ahead. Like most of the other systems listed here, it first flashes a warning light on the dash and pre-charges the brakes.
The new XC60 crossover also adds a new standard feature called City Safety that's designed for urban stop-and-go driving. It uses sensors in the windshield to monitor the vehicle ahead when the XC60 is traveling between 2 and 18 mph. If the car in front slows or stops, City Safety automatically applies enough brakeforce to either slow or stop the vehicle in order to avoid a fender bender.
