See this is where it gets complicated!
This is complicated! But this thread is in answer to a comment from Tirrill in an off subject post about speed limit signs in the Cruise control thread under Tow cars and Towing section. To have answered it directly would have again gone off thread!
So Tyrill said that some of the most effective speed limit signs, are those painted on the road surface itself rather than on signs on poles as is the norm.
Many people do not realise that those Road surface signs are frowned upon by the DfT who are very strict about their use.
Firstly, they point out that all motorists should know of the existance of a speed limit by the fact that there are, or are not, street lamps. So (other than those at the start and end of a limit) No reminders are permitted where the limit is 30 and there
are street lamps. You may erect or paint on the surface of the road reminders where there are no street lamps. BUT those painted on the raod surface, can only be placed close to the start and end of a section NOT at intervals throughout!
In similar fashion because the existance of street lamps normaly denotes 30 mph, then where the speed limit again varies from 30 then repeaters of the actual limit must appear at regular intervals during that section, - and painted on the road at the start
and end but not throughout!
There we are Children I hope that that is all clear!
TF