We have warning signs posted in areas where speed cameras are posted... I'm not sure though for mobile / handheld traps.
The signs have a picture of a camera and the words " Police Safety Cameras in Operation" and stuff like that.
Here's a parody:
They're becoming a joke in thre UK. They're everywhere and the number of real policemen in traffic vehicles is dwindling. This means more people are being stopped for petty speeding offences, while drugged up / drunk drivers in unsafe cars are getting away with it!
I'm all for speed reduction where neccessary, but seriously, these cameras and mobile units are everywhere.
/rant
