What the best radar detector has
- Radar detection on all bands. The types of radar bands used in the U.S. are X-, K- and Ka-band radar. A good detector will accurately spot them all.
- Laser detection. All good radar detectors will also sniff out laser guns -- although by the time a detector notices the tiny laser beam, you've probably already been flagged for excessive speed.
- "Quiet" detection modes. "City" and "auto" modes drastically turn down X-band sensitivity to reduce false alerts from automatic supermarket doors and the like. K-band filtering tones down false alarms from vehicle collision warning systems, blind spot monitors and similar systems.
- Voice alerts. Aside from the usual readouts and beeps, all top-rated radar detectors -- even lower-priced ones -- now offer spoken alerts as well.
- Mute and auto-mute. To quiet ongoing alerts (for example when the radar gun is still far away), you can press the detector's mute button; all top-rated detectors also auto-mute, or turn the volume way down after the first few seconds of an alert.
- Good ease of use. When your radar detector is blasting a warning, you won't have time to sort out anything complicated.
- A one-year warranty. This is pretty much the current standard; you can also purchase longer warranties.
Know before you go
Do you drive more in the city or on the highway? Highway drivers usually want the most sensitive detector possible -- one that will give them the earliest warning of a looming speed trap, so they'll have time to brake from high speeds. City drivers may prefer a "smart" GPS-equipped detector that blurts out fewer false alarms from urban and suburban radar sources (like automatic door openers). Only really expensive models, like the Best Reviewed Escort Passport Max 360 (Est. $635), excel at both.
Do you drive past speed or red-light cameras? GPS-equipped radar detectors have built-in databases (usually updateable, though some require a subscription) of thousands of these cameras nationwide, so they'll warn you whenever you approach one. As of January 2017, 425 communities have red-light cameras and 142 have speed cameras (including statewide work-zone programs in Illinois, Maryland and Oregon); check the Insurance Institute for Highway Safety's website to see if yours is one of them.
Are there Laser speed guns in your area? If so, even the most expensive radar detector probably won't help you. Laser beams are just too small and precise. Every radar detector in this report can detect Laser guns -- but usually not until it's too late.
What about a Laser jammer? Laser jammers are available, but these are expensive and can quickly become obsolete as speed-detecting technology advances. The industry has seen many jammer makers come and go, leaving users with useless, unsupported hardware. These devices are also illegal in several states. Because of that, we've chosen to not recommend a Laser jammer in this edition of the report.
Driving carefully is the best defense against speeding tickets. It's also important to realize that no radar detector will report every single radar encounter. There are too many variables, such as terrain, angle of the gun to the car, interference from other traffic, etc. Although certain models do better than others, no radar detector will spot 100 percent of radar threats 100 percent of the time. If you want to be absolutely sure of never receiving a speeding ticket, the only sure defense is to not exceed the posted speed limit.
What are the different kinds of speed detection radar? Before you purchase a radar detector, it's important to understand the different kinds of radar used to detect speeding. Radar guns work by emitting a microwave pulse to measure the speed of a moving vehicle; radar detectors work by sending out a signal that mixes with this pulse to produce a lower, more easily detected frequency.
X-band radar (10.5 to 10.55 GHz) used to be the most popular type of radar gun used, but it is now all but obsolete. X-band is also the frequency that causes the most false alarms. That's because many supermarket automatic doors, garage-door openers and motion detectors run on the same frequency. Even inexpensive radar detectors often have a city mode that lets you downgrade or disable a detector's sensitivity to X-band, thereby cutting down on the number of false alarms from sources other than law enforcement.
The majority of radar guns operate on the K-band (24.05 to 24.25 GHz) or Ka-band (33.4 to 36 GHz) frequency. K-band and Ka-band guns are especially tricky because they can be turned on instantly. If one is trained on your car, it's almost impossible to be warned ahead of time. However, good detectors can provide a warning if a radar gun is targeting vehicles ahead of yours, giving you enough time to slow down.