Is a radar detector worth the price?
Aside from going the speed limit or employing psychic powers, you probably won’t know a cop is pointing a radar gun at you until it’s too late.
A radar or laser detector device may help you avoid a speeding ticket — and higher auto insurance rates — by alerting when you're being tracked by radar. Keep in mind that experts say they're not always worth the cost, with the price of a detector ranging from about $100 to $500.
Jason Kavanagh, engineering editor at automotive website Edmunds.com, points out that "radar detectors do not guarantee a clean driving record."
Still, a radar detector might keep you from being nabbed for speeding — and paying more for auto insurance.
Speeding tickets can increase your car insurance premiums by 30 percent, says Rose Marshburn, personal lines specialist at SIA Group, an insurance agency in North Carolina. How much your rates go up depends on your insurer, says Kevin Lynch, assistant professor of insurance at The American College in Pennsylvania.
Legal in most states
In the United States, motorists can use radar detectors except in Virginia and the District of Columbia, says Kristin Nevels, a spokeswoman for the nonprofit Insurance Institute for Highway Safety. More than half of drivers who use radar detectors admit driving faster than they would have without the devices, Nevels says.
On its website, the National Motorists Association, a nonprofit advocacy group, says: "There is no evidence to suggest that radar detectors encourage speeding or make motorists drive faster than they would otherwise."
In general, radar detectors are a waste of money for consumers, says Sgt. Jimmy Chavez, president of the Arizona Highway Patrol Association. "By the time the device alerts the driver," he says, "they've already been clocked on radar by the patrol officer."
Radar detectors and their younger siblings, laser detectors, someday may be irrelevant. Many law enforcement agencies have switched to something called LIDAR (Light Detection and Ranging) guns instead of radar guns, says Lee Wade, assistant professor of criminal justice administration at Middle Tennessee State University. Radar uses radio waves to track speed, while LIDAR relies on laser light beams.
"In my experience, LIDAR provides a more accurate detection of the violator speeding,” Wade says.
With radar guns, cops use their own judgment regarding whether a vehicle is speeding, Wade says, and the radar confirms their estimations. LIDAR removes the judgment aspect.
Chavez says the Arizona patrol uses Visual Average Speed Computer and Recorder (VASCAR) radar, which measures speed based on distance covered within a certain time frame. "It does not emit a signal … and cannot be picked up by a radar detector," he says.
The National Motorists Association opposes the use of radar and laser devices by cops trying to catch speeders.
"Both technologies have inherent flaws, making them unreliable for speed enforcement, and their use encourages the proliferation of speed traps, which are fundamentally unfair to motorists," the association says on its website.
When detectors can help
Some experts argue that radar detectors can help you avoid a speeding ticket. In some instances, they can pick up a radar signal a mile or so in advance, Edmunds.com's Kavanagh says.
But if a laser-equipped cop catches you, a speeding ticket probably will be issued, he says.
"These are aimed at specific cars, operate at the speed of light and don’t emit stray signals like radar does," Kavanagh says. "With laser detectors, by the time it delivers its alert, it’s usually too late."