Modern Cars Wreak Havoc on Radar Detectors
28 comments
·August 13, 2025yugioh3
unshavedyak
I just wish cops would actually do that more frequently. My local interstate is basically only trapped during a small window a day, easy to memorize.
I don’t blame people for speeding when we care so little as to actually monitor and enforce. Especially when it’s easy to automate.
The_President
Lotta miles using radar detectors -- they detect 3 different bands of radar and some "detect laser." Radar detectors are great insurance, and more useful on the open highway than they are in town, but I've not seen a vehicle give off Ka band emissions that wasn't law enforcement. I have noticed that newer Honda cars set off the K band, which is also used by a lot of the cheap lightpole "your speed" I've seen. Very rarely still I will see X band speed radar being used in the middle of nowhere where the cop cars are older.
Radar detector users just learn to ignore the X and K band alerts while simultanously learning a subconscious quarter second brake reaction time based on the Ka band noise.
aussieguy1234
These detectors have been illegal in Australia for as long as I can remember. But with apps like Waze and TomTom Amigo, I probably don't need them. I can see where all the speed cameras are and police get reported on the map fairly quickly (I also contribute to these reports, let's subvert government power together)
gwbas1c
If anyone's still reading this: As I read this, I think it makes more sense for the police to replace radar with a high-resolution camera and a computer that can determine speed of vehicles.
Any thoughts on that?
EA-3167
It's hard to find exact stats because of how procurement and statistics works across jurisdictions, states, etc... but from what I CAN find it seems that LIDAR is more common than Radar these days. Over the whole country it looks like a slight majority lead for LIDAR, but in some (quite populous) states they almost only use LIDAR (PA for example had 93% of their tickets come from LIDAR, and I believe most of the rest used speed cameras or 'clocking' rather than RADAR).
Sources:
https://www.legis.state.pa.us/WU01/LI/TR/Transcripts/2018_00...
https://en.wikipedia.org/wiki/Lidar_traffic_enforcement
https://www.ojp.gov/ncjrs/virtual-library/abstracts/lidar-sp...
toomuchtodo
LIDAR can't be used in motion, the LEO has to be stopped to be pointing it. Your laser detector will warn you, but it's already too late at that point; my two cents is using Waze/Google LEO alerts is state of the art at this point (until someone starts multilateration of patrol cars using their radio RF emissions and SDR networks).
bob1029
> LIDAR can't be used in motion
To be clear, the reason for this is because the width of the beam requires aiming it like a sniper rifle, not because we can't compensate for operator motion.
netsharc
It's fine... if you're fine with constant video surveillance.
gwbas1c
There's a huge difference between a network of cameras on a road, versus a device that an officer has to set up and take down.
stefan_
Its like the dumbest product manager meme. “Humans use eyes for this right, why can’t our gadget?” “It must work at night? Oh we will just use a thermal camera” “Pixels in an image are not all from the same time instant? We will just pay 10x for a global shutter camera”
The list goes on and on and on. No, they will not just be replaced by whatever is producing loose AI facsimiles of the real world in a smartphone.
adgjlsfhk1
you can also just use a normal rolling shutter camera at a higher frame rate and blur the frames together.
steve_gh
...or you could drive sensibly within the speed limit.
devilbunny
Make the speed limit sensible, and I will.
I don't speed in Europe because 130 km/h is a perfectly fine limit; I've driven faster on uncontrolled Autobahn segments, but I'm not bothered when there is a limit. 65 mph on the NJ Turnpike (and only on the southern part) is not.
yugioh3
65mph is plenty fast. going beyond 70/75 is diminishing returns in the safety of other drivers, not to mention worse greenhouse emissions.
a crash at 80+ is so much worse than one at 65. and American highways are not the Autobahn. different design and engineering.
marssaxman
Which one is it, driving sensibly or driving within the speed limit?
Spivak
Yeah the internet it weird about speed limits for some reason meanwhile the moment you drive on real roads in the US you lean very quickly, even explicitly if you did in-cars in driver's ed, that the posted speed limit is the minimum.
dmd
There are roads here that “feel” like a 35 or even 45mph road. The speed limit is 7. Yes, 7. It’s purely for local revenue.
vasco
Can of spray and a night off and they all become 70
bsder
Then set the limits properly at the 85% mark. And ban speed limit fines from going into local coffers.
01HNNWZ0MV43FF
Dare I ask what the 85% mark is?
The_President
There are back roads out there that drop 15 mph at the state line with no population around for miles. Detectors offer peace of mind for travel at a leisurely self-determined rate.
gwbas1c
What fun is that?
That being said, "speed culture" varies a lot from state to state. Where I live it's assumed and expected that you will speed, and in other areas you can get a ticket for going 1 over.
The legal and cultural ambiguity means that someone who is unsure of the real, enforced, culturally-accepted speed limit may want to use a radar detector.
rogerrogerr
Yup, in Idaho you’re pretty much expected to do +5. I swear they figure out the proper speed and subtract five from it. Going the speed limit will get you run over.
HeyLaughingBoy
...on the long (9 miles to the next town), straight county road just by my house with a 50 mph speed limit that sees maybe 1 car per minute on average. There's a reason that the average speed there is 65mph+
good. speed kills. off highways, speeding is particularly dangerous for pedestrians, cyclists, and other drivers.