AndyS
November 2018

Merge in turn signs, now prescribed under Schedule 13, Part 9, must not be used in a permanent situation, unless authorised by DfT. I seriously doubt if DfT would make such an authorisation.

There are specific criteria to use them, as stated in Chapter 8.

Why do you feel there is a need to use these signs in a permanent situation? I can think of no valid reason at all.