Speed sign doesn't use radar?

[spyder2000]

My town is installing new speed signs to display vehicle speeds. I thought this was a great idea because now there would be at least four known locations to test detectors with.

I passed one last week. It was displaying vehicle speeds but didn't trigger a detector (X-50) which alerted normally to a door opener a short ways past it.

Kind of puzzled by this and will check it out a bit more and see if I can determine manufacturer.

[languy99]

it might be laser based. Almost no RD can detect laser reliably, only the v1 can to an extent.

[STiMULi]

My town is installing new speed signs to display vehicle speeds. I thought this was a great idea because now there would be at least four known locations to test detectors with.

I passed one last week. It was displaying vehicle speeds but didn't trigger a detector (X-50) which alerted normally to a door opener a short ways past it.

Kind of puzzled by this and will check it out a bit more and see if I can determine manufacturer.

Could be induction based (in the road)

[Beatlesfan]

Most likely the radar sign drifted so far out of tune the RD didnt pick it up.

[kpatz]

Some signs use modulated directional radar to only clock the speeds of approaching cars (while ignoring traffic in the other direction).

RDs filter out modulated signals to reduce falsing.

[redrider]

I passed one that my V1 won't pick up. When I went back with the Escort 9500ix, it picked it up just fine. Went back again with the V1, and still no signal. The V1 works fine in all other encounters and was recently sent back to Valentine and checked out. Not sure why, but for some reason, it doesn't always pick up many of these signs.

[Motor On]

My town is installing new speed signs to display vehicle speeds. I thought this was a great idea because now there would be at least four known locations to test detectors with.

I passed one last week. It was displaying vehicle speeds but didn't trigger a detector (X-50) which alerted normally to a door opener a short ways past it.

Kind of puzzled by this and will check it out a bit more and see if I can determine manufacturer.

Have a photo of the sign?

[voyager7]

it might be laser based. Almost no RD can detect laser reliably, only the v1 can to an extent.

Just asking. How can a speed sign or red light cam be laser activated when the laser has to be aimed by hand?

[Motor On]

it might be laser based. Almost no RD can detect laser reliably, only the v1 can to an extent.

Just asking. How can a speed sign or red light cam be laser activated when the laser has to be aimed by hand?

Fixed sign, aimed at a fixed lane, no different than using a tripod except it's built into the sign and aimed when installed.

[Beatlesfan]

it might be laser based. Almost no RD can detect laser reliably, only the v1 can to an extent.

Just asking. How can a speed sign or red light cam be laser activated when the laser has to be aimed by hand?

Fixed sign, aimed at a fixed lane, no different than using a tripod except it's built into the sign and aimed when installed.

But do they exist?