In 1989, AOL Editor-in-Chief David Kiley was in a collision that could have taken his life. He was driving a Buick Roadmaster, a heavy aircraft-carrier of a sedan. As he was stopped in a left-turn lane, he looked up at the light to see if it was time to turn into the intersection. The light he looked at was green, but it was the wrong light; it was for the through traffic. His light was still red. As he turned, admittedly distracted by some personal family events that were occupying his mind, the oncoming Volvo 240 stationwagon barreled into Kiley's Roadmaster, T-boning the car.

The Volvo occupants were fine, though quite dazed. Kiley's Roadmaster was a total, but he was spared, in part, by the airbags that deployed.

If one or both of those cars had been equipped with collision-avoidance systems offered on many cars today, the accident may have been avoided all together. It's important to realize, says Kiley, "that I had been driving a Mazda Miata in the same spot a few days earlier, and I daresay I would not have been as fortunate."

Collision avoidance systems are appearing on more and more cars, big and small, as options, or as part of safety packages car companies are offering. Do they work? How do they work? Read our Techsplanations on today's collision-avoidance system:

What is it?

Collision avoidance is the next frontier in safety. Ever since seat-belts became mandatory equipment in the 1960s, most safety improvements have been focused on surviving an accident. From impact-absorbing bumpers to multiple airbags, the idea has long been to make a car more able to take a hit and still protect its passengers. Automakers have been very successful in their efforts, so now they're turning towards using technology to help cars avoid accidents altogether. The cars are literally becoming smarter than we are as drivers.

How does it work?

Collision avoidance generally starts with a system called adaptive cruise control. This is like regular cruise control, but with the addition of radar sensors that can "see" the traffic ahead of you and slow your car to maintain a safe following distance. If you are a notorious tailgater, this system over-rides your own bad driving habits.

Collision avoidance systems can also sound alarms or flash warnings on the windshield if the sensors determine that your car is getting to close to another car too fast. The system will then apply brake pressure perhaps sooner than you yourself would. If the computers and sensors determine that a crash is unavoidable, they also work to tighten up seat-belts, adjust headrests, or close the power windows and sunroof to make the car safer in the collision. Pretty nifty.

Collision avoidance also includes other related technology, like lane departure warning and blind spot monitoring systems. This technology works by using a camera to "see" the road and alert the driver if the car begins to drift out of a lane, or if another car approaches from the side. Lane departure warning systems will sound warning tones or vibrate the steering wheel, and some may even help steer the car to keep it headed straight. Blind spot monitoring systems often display warning lights in the driver's peripheral vision and may sound alarms as well. Some systems use radar rather than cameras, but the end result is the same.

Why would I want it?

Simple: It makes your car safer. Avoiding accidents isn't just good for your health, but it saves time and money that would be spent dealing with the aftermath of a collision, too. These systems react faster to dangerous situations than we, as people, ever can.

Is there any downside?

None really, save for the occasional annoying beep or steering wheel vibration when the system over performs and reacts when there isn't what you might call "real danger."

What vehicles offer it?

This is the sort of technology that's become prevalent on luxury cars, like Audis, BMWs, and Cadillacs, but it has begun to trickle down to more mainstream vehicles like the Ford Taurus, which offers the system standard, and Dodge Charger, as well. Within a year or two, even cars priced below $20,000 should be offering these systems for as little as a $500 option as there is mounting pressure on car companies to make it standard equipment, or a modestly priced add-on.

Bottom line

No matter how good a driver you might be, there are times when it can't hurt to have a little technology on your side.