Safety plays a varying role in the purchase decision, but most consumers consider it very important these days. The 1999 crop of new vehicles boasts a number of new safety features worth your consideration. Even more advanced safety items are scheduled for introduction over the next several years.

Just how far safety technology can go is demonstrated in prototype vehicles such as Toyota's Advanced Safety Vehicle. It's equipped with a hood airbag for pedestrians, side-mounted cameras in the front fenders so you can see cross traffic as you peek out of a narrow alley, a fire suppression system for the engine compartment, a drowsy driver alert, and an automatic accident avoidance system.

Gentler Airbags

Airbags haven't lived up to the cure-all safety reputation they once had. To be sure, the devices deserve credit for saving thousands of lives. But their explosively fast inflation rate also has been blamed for injuring or killing occupants who were sitting too close to them when they deployed.

Until the 1998 model year, the airbags were engineered to meet federal safety regulations requiring them to protect an unbelted adult male in a 30-mile-per-hour frontal crash into a barrier. Modified test standards now permit airbags that deploy with up to 35% less force.

These gentler airbags still inflate faster than the eye can see - they must if they are to provide protection in time. Virtually all 1999 cars and trucks are equipped with some form of these less forceful airbag systems. A few automakers are introducing two-stage airbag systems that are smart enough to inflate with less force at lower crash speeds.

Many 1999 models come with side airbags as well. Mounted in the doors or outer edge of the front seats, they pop out to protect your torso in a side impact.

That's not all. Manufacturers such as BMW, Mercedes-Benz, Toyota, and Volvo are adding a second set of airbags-shaped like tubes or curtains-that block the side windows to protect your head and keep you inside your vehicle when you're hit from the side. Developers have even come up with small footwell airbags to protect your feet in a crash.

Still smarter airbags are expected a few years from now. They will determine the weight and location of each passenger, check for seatbelt usage, and note the speed of the vehicle in deciding how much force to use in deploying. The hardware for such systems exists today, but developers are still working on computer software that can accurately make the necessary calculations in a split second.

Smart Tires

Even the tires on your car are beginning to get smarter. Continental General Tire is developing a technology that lets tires "read" the road as they roll along, relaying the information to a special suspension that responds to changing road conditions and driving styles accordingly.

The Continental system imbeds magnetic bands in a tire's sidewall, then uses a pair of sensors to read their movement. The result is a stream of data about tire loads that could be fed into antilock brake and active suspension systems to improve their performance.

Modern tires make blow-outs less likely. But if you're still worried about getting a flat, look into the new and growing breed of run-flat tires. Run-flat technology isn't new, but marrying it successfully to conventional tire rims has taken time. You'll find run-flat tires in sizes to fit most cars and minivans. They look like conventional tires on the outside, but their sidewalls are stiffer so the tire won't collapse when it loses air. The tires are so effective at maintaining their handling characteristics after a puncture that run-flats generally require special sensors to warn you when they lose air.

Even tires with no built-in brains are more competent than previous-generation rubber. The trend is to superior performance and greater durability under a broader range of driving conditions. Most tires on new American cars today have all-season capabilities, for example. And high-performance tires are beginning to match the longer tread life that more sedate tires achieved years ago. Some are adopting tread patterns originally developed for wet weather racing tires, a feature that helps avoid aquaplaning - the skid-prone condition that occurs in rainy weather when a tire can't squeegee away water fast enough.

Lights On For Safety

Should your headlights be on during the day? Many safety experts think so. Research is inconclusive on the issue, but the idea of using your headlights to make your vehicle more noticeable to other drivers during the day certainly appeals to common sense.

Daytime running lights (DRLs) are required on new cars sold in Canada and Scandinavian countries. There's no rule about it in the United States so far, but several brands offer this feature anyway, including GM, Saab, Volvo, and Toyota.

A Smarter Dummy

How effective are airbags, seat belts, and other automotive safety items? Ask a dummy.

For years, key safety performance information has come from Hybrid III, a crash dummy developed by GM. Hybrid IIIs have been riding out and reporting the effects of frontal, side, and rollover crashes for years.

Now a more intelligent dummy, Thor, is preparing to take over early in the 21st century. Built to mimic the behavior of the human body more accurately than its predecessor, Thor promises to give researchers a clearer picture of the forces affecting the body during a crash. The new dummy features 120 built-in pressure sensors, about twice as many as a typical Hybrid III has. It's also configured to measure forces generated by seat belts, airbags, and other safety systems that were still in their automotive infancy when Hybrid III was designed.

Suspensions That Think

Your car's suspension waits until you hit a bump, then reacts by trying to minimize the jolt. But one day it will "read" the road instead, then adjust itself before the bump arrives so you can enjoy a boulevard ride and sports car handling at the same time.

In their most advanced form, these active suspensions require no springs or shock absorbers. None is in mass production, though, because of the high cost of the sensors, high-pressure hydraulics, lightning-fast actuators, and high-tech computers necessary to make it all work.

In the meantime, you can buy some cars that use their antilock braking and traction control systems to help prevent skids. Lexus Vehicle Skid Control, for example, will dial back engine power and apply braking to individual wheels as necessary when the direction of vehicle travel does not agree with driver steering input. Other luxury cars-notably those from Audi, BMW, Cadillac, and Mercedes-Benz-offer similar systems. Bosch is credited with developing the first skid control system four years ago.

Other manufacturers offer adaptive transmissions that shift sedately or aggressively according to how you use the accelerator. Some can adjust their shock absorbers automatically as road conditions change.

Another technology you'll hear more about in the next few years is adaptive cruise control. It uses radar to check on the car ahead, adjusting your speed automatically when traffic slows or someone pulls in ahead of you so you don't have to repeatedly engage and disengage the system.