They're not very consistent as to their accuracy, sometimes there's a 5mph difference between what my speedo shows as 30mph and what the sign says is 30mph. The local council has 1 in a certain place at random times and the accuracy is different each time.
Radar signs are extremely accurate (in theory, more accurate than measuring speed with GPS), whereas car speedometers tend to display the speed slightly higher than it actually is. If the accuracy of your local radar signs changes after each installation, it could be due to the signs being installed at the wrong angle or being incorrectly calibrated.
@@StartSafetyUK Must be the calibration then, as the pole that it's installed on when it's there is permanently in place. I've no idea how many locations the sign is rotated around. Think it must run off of batteries as there's no solar panel there, and after about a week or so it stays blank all the time
@@leeroberts1192 Sounds like they really should get a solar panel then. In any case, a battery life of only a week doesn't sound too good, as ours should last for about a month under normal use. Unless the road is exceptionally busy of course.
