DOUG BEDELL
Technology Writer

When Craig Peterson lead-foots his way nonstop from Denver to Houston each year, his high-performance sports car carries the most sophisticated consumer radar detectors on the market.

His front grille and rear bumper are wired with elaborate sensors - part of a $1,600, professionally installed "remote" unit, the most expensive available. Inside the cockpit, a special handheld scanner constantly searches for police radio transmissions. His eye constantly scans a blinking panel of lights designed to warn him if he's headed for a speeding ticket.He says he's had only one since 1992, but every year he feels more vulnerable.

And if Mr. Peterson - one of the nation's foremost experts in police speed detection technology - feels that way, the average driver with a $100 radar detector should feel positively defenseless.

"It's not widely known, but there are only a couple in the $100 price range that have the sensitivity to be a useful countermeasure," he says.

Cat and mouse

In recent years, the cat-and-mouse contest between "Smokey" and the scofflaws has been gradually tilting toward law enforcement. Meanwhile, the Consumer Electronics Association says between 10 million and 20 million drivers traveling American roads today are packing some form of radar detector, usually a low-priced unit that Mr. Peterson considers worthless.

The arms gap has widened as police nationwide have begun phasing out older radar guns that operate on two frequencies, X-band and K-band. In their place lower-powered, digital Ka-band guns and even more stealthy laser-based speed detectors are increasingly deployed.

Mr. Peterson's most recent 3,000-mile round trip from Denver to Houston illustrates the problem faced by the modern-day road warrior. Of 11 encounters with radar, he reports, one was X-band, three were K-band and seven were Ka-band units. That mirrors national trends, he says.

Of the estimated 100,000 radar guns now in service only about 15,000 are X-band, the most easily spotted by consumer dash-mounted detector units. About half of the rest are K-band, and 35 percent operate with Ka-band, Mr. Peterson estimates.

As lightning-quick Ka-band radar guns and lasers rapidly replace clunkier technologies, Mr. Peterson and other experts say, the consumer technologies for detection have fallen behind.

Mr. Peterson, the author of Fast Driving (Without Tickets), has conducted more than 30 comparison tests on commercially available radar detectors, which he posts at RadarTest.com. His advice often appears in Automobile magazine, and he is often summoned as an expert witness in court cases involving consumer radar detector technology.

Comparing notes

But his findings and those of other experts in the field are still the subject of heated debate among consumers and industry professionals. On Internet news groups such as rec.autos.driving, consumers are constantly discussing testing procedures and sharing experiences with top brands.

Most users don't expect perfection. They knowthat radar units can track them up to two miles away, although technically, officers must witness a violation, visually estimate the target speed and, only then, activate radar to confirm that estimate, Mr. Peterson says.

At best, dash-mounted detectors help spot troopers mechanically before the driver can see them. Or the units bark warnings when nearby cars are being tracked, allowing time to decrease speed. In general, though, if your car is the first to be hit by a detecting device, the trooper can accurately clock you before you can react, experts say.

The legalities

Legal issues are fairly clear-cut. In Texas and the rest of the United States, except for Washington, D.C., and Virginia, radar detectors are legal for everyone except big-rig truckers and buses carrying more than 15 people. Maj. Coy Clanton of the Texas Department of Public Safety says troopers are largely indifferent about their use in passenger cars.

These days, even with older X-band radar, troopers can silence their equipment until they are ready to fire at a suspected speeder.

"The operator can switch on the radar so instantaneously that there's no chance to slow down," says Maj. Clanton.

Manufacturers, sensitive to limitations of their technologies and criticism from police, have begun marketing their products as "safety enhancement" or "highway information" products that keep drivers alert to their surroundings.

Others monitor emergency vehicle voice transmissions to warn of possible accident activity. To differentiate between those warnings, many have added digital read-outs that can be used instead of distracting beeps and chirps.

Testing of most consumer radar detector units has shown "dismal" results in detecting Ka band signals, says Mr. Peterson, a certified police radar instructor. In fact, several didn't sound an alarm until test units were parked right next to a Ka-band gun, he says.

In overall sensitivity rankings of the best-selling commercial radar detectors, Mr. Peterson ranks the Beltronics BEL 890 (about $200) and slightly less expensive BEL 880 at the top of the heap. Among more expensive units, top performers are the Beltronic Vector 900 series ($290 to $499), Escort Passport 8500 ($299) and Valentine One ($399).

If you're considering one of the dozens of radar and laser "jamming" devices sold in auto supply stores and on the Internet, Mr. Peterson has some simple advice.

"Ninety percent of them are pure consumer scams," he says. Five states - California, Minnesota, Nebraska, Oklahoma and Virginia, as well as Washington, D.C., have made it illegal to employ jammers.

"If an experienced officer thinks you have a jammer, it's going to complicate your life," he says.