Reader Question: Radar Detectors Still Worth It?

Print Friendly, PDF & Email

Here’s the latest reader question, along with my reply!

Kristin asks: Is it still worth getting a radar detector given how many cops use Instant On to peg “speeders”? My understanding is that radar detectors are only or at least mostly effective only against a steady radar beam, which they can alert you to in time to reduce speed and avoid the ticket? Is that still true?

My reply: There is truth in both.

Yes, it is true that many AGWs use Instant On radar to “peg” (perfect word choice) people who drive faster than the arbitrarily decreed maximum allowable speed. And yes, it’s true that it is harder to detect Instant On in time to reduce speed.

But it is also true that not all AGWs use Instant On. And it is also true that a good radar detector can detect Instant On in time… if the targeted car is ahead of you. This will give you time to slow down.

It is generally sound policy to avoid speeding by yourself. The best policy is to let someone else speed ahead of you. To run point, as the military saying goes. If you are the only car on the road, you are also the only target on the road. Tread carefully, even with countermeasures such as a radar detector at hand.

Also, buy a good radar detector, if you’re going to buy one at all.  Like the latest generation Valentine1, which has arguably the best filtration system and sensitivity on the market. Well worth the expense, in the same way that good tires are worth the expense. The cheap ones wear out sooner – and end up costing you more. The bad detectors don’t detect as effectively – and end up costing you more.

No countermeasure is foolproof. But this is about reducing the odds – or rather, increasing the odds in your favor – that you won’t get a piece of payin’ paper.

And in that sense, a radar detector is money very well spent!

. . . 

Got a question about cars, Libertarian politics – or anything else? Click on the “ask Eric” link and send ’em in!

If you like what you’ve found here please consider supporting EPautos. 

We depend on you to keep the wheels turning! 

Our donate button is here.

 If you prefer not to use PayPal, our mailing address is:

721 Hummingbird Lane SE
Copper Hill, VA 24079

PS: Get an EPautos magnet or sticker or coaster in return for a $20 or more one-time donation or a $10 or more monthly recurring donation. (Please be sure to tell us you want a magnet or sticker or coaster – and also, provide an address, so we know where to mail the thing!)

My eBook about car buying (new and used) is also available for your favorite price – free! Click here.  If that fails, email me at and I will send you a copy directly!


  1. As someone who has run a radar detector for over 25 years, I completely agree. I’ll add the following:

    1. Yes, Instant-On is slightly harder to detect, but most halfway decent detectors today will pick it up very quickly. This isn’t helpful if YOU are the one being targeted, but it will alert if someone in front of you is hit first and you have a reasonably good line of sight to them.

    2. Higher end detectors can pick up radar signals a mile or more ahead on reasonably straight highways and interstates. I regularly pick up police 3+ miles ahead on longer, straighter stretches of roadway, especially if I crest a hill and the detector can “see” farther ahead. This is one reason why experts recommend placing the detector higher up on the windshield rather than at dash-level when practical.

    3. Higher end detectors tend to have better processors in them which permits more sophisticated filtering of false alerts. Many newer vehicles (especially Honda, Acura, and GM) in the past 10 years or so have proximity systems for blind-spot monitoring that operate on the K-band frequencies and will fool most detectors, even modern ones, sometimes. Detectors are getting better at filtering these, but they still have a long way to go.

    4. GPS lockout is invaluable if you drive the same routes repeatedly. The stationary false alerts such as motion sensing door openers (e.g., pharmacies, grocery stores) and some security systems are everywhere but do not move around. GPS lockout capable detectors can remember and lockout a particular frequency of radar signal within a predefined radius of the GPS coordinates that signal was found to be strongest (or where you mark it). Most can “unlearn” this if you pass by this position multiple times without that signal being detected. Other radar in that area will still alert the detector. It’s common for police to position themselves within proximity to false alerts like grocery stores and run their own radar guns. Additionally, psychologically, the detector is much quieter, perhaps 90% quieter, so when an alert happens, you are much more likely to pay attention rather than assume it is a false alert.

    5. Laser guns are MUCH harder to detect than radar because they don’t scatter as much, but they DO scatter. Laser guns are not nearly as commonly used as radar guns, and when I’m in parts of the country where they are more common, I WILL detect them sometimes with a lead time because they tend to scatter more than people realize. They must be aimed into oncoming traffic, and it’s impossible to hold the gun entirely steady. Just like a laser sight on a firearm, the laser gun speed measuring device will wobble around in the operators hand. Even subtle movements of the vehicle itself as the engine is running will translate to a wavering of the laser beam by a pretty large amount at a distance. The target vehicle may be close, but the laser will reflect and scatter, or the gun will wobble in the operator’s hand/vehicle, and laser “splatter” will travel further down the road towards oncoming traffic. Still, though, this is a much greater threat than Instant-On radar. And many brake lights, and even the setting sun, can give false alerts on many detectors.

    6. Run Waze in conjunction with a detector. This is navigation software (owned by Google) with crowd-sourced reports of police spottings, accidents, obstacles on road, etc. If a user ahead reports a road pirate (police), they will report it and your app instance will warn you many miles ahead.

    7. And, as Eric mentioned, don’t run solo out in front. Similarly, don’t run fast at night, especially if traffic is light. It’s impossible to visually spot a pirate ahead of you at night in the dark, but they’ll see you from miles away by spotting your headlights. If nobody, or few people, are ahead of you in traffic, you very likely win the prize of getting pegged.

    Now if only Mr. Valentine could invent vehicle-based radar-hunting SAMs (Surface to Asshole Missiles).


Please enter your comment!
Please enter your name here