can anyone settle a debate please. if a driver is driving in excess of the speed limit on a motorway, will a camera flash as they do on normal roads or are there hidden cameras that will clock ones speed and you will just get a letter in the post
But of course they are not average speed ones. They are, "we are telling you to go ridiculously slowly for no apparent reason except to catch you out", ones.
most do not flash these days, most are ANPR. The old "Gatso" with analogue film are mostly gone. There are some average speed ones and they don't flash either. There are not hidden generally though placement may give that impression.
If they don't flash then they don't modify your behaviour that day, and possibly not until you have too many points to want to risk another. It would be a way to collect maximum income, deliberately.