Fluorescent yellow stickers on the rear of road signs

[ALBA MELV]

Morning all,

Recently I've noticed new fluorescent yellow stickers on the rear of two road signs within about 100m of each other. My assumption is that these are for calibration of speed cameras in either a (s)camera van or police vehicle, is that correct? If not any idea what they are for?

The places I have seen these stickers on signs would be in the line of sight of speed guns, etc when the BiB are sitting it their usual secluded spots waiting to pounce.

Here's some other markings on the A96 whick I've noticed, the google map image hasn't been updated for the new ones.

https://www.google.fr/maps/@57.406454,-2.697997,3a...

https://www.google.fr/maps/@57.404723,-2.694319,3a...

[Rovinghawk]

Do they look similar to this, albeit yellow? Land surveyors use them for positional fixes.
http://surveyequipment.com/surveying-accessories/r...

Ideally they need to be slightly elevated & easily found from a distance- the back of a road sign would be ideal for this.

[ALBA MELV]

Rovinghawk said:

Do they look similar to this, albeit yellow? Land surveyors use them for positional fixes.
http://surveyequipment.com/surveying-accessories/r...

Ideally they need to be slightly elevated & easily found from a distance- the back of a road sign would be ideal for this.

Afternoon

Nope, the ones in my links are just plain fluorescent orange, the new ones I spotted recently are plain fluorescent yellow.

[Nickyboy]

They also use things like that for marking the edge of road for snow ploughs