Speed only display:



They don't tend to use these any more because people used to have races to see if they could get it off the scale. Some now display the speed if you are under it but frown if you go over it. Some also display your number plate eg. "Y123 ABC - 45mph".

We've had a flashing "SLOW DOWN 30" sign near our house for 15 years and it works well, much better than a speed camera and you don't get people necklacing them, or, more spectacularly, blowing them up.

Finally, the SID smiley:



This comes from a report about one that was stolen! Somebody probably thought that it had a camera attached and they had been done (and were going to get a ban due to "totting up" and going over 12 points)

Gareth