Any roads that were previously 30 will now be 20 apart from the roads that aren't going to be 20, which will still remain as 30. When you see street lights you have to assume that the roads will be 20 even if the signs still say 30 because despite the signs saying 30, the roads could be 20, apart from, of course, the roads (as explained above) which will remain 30 despite them being 20. It's also important to remember that there will still be a number of roads which despite them having streetlights will not be 20, and in these cases they could be 30, 40, 50, 60 or even 70, however, always bear in mind that even if the signs on these roads still state 30 they could, of course, be 20 unless they are one of the roads that have been designated 30, in which case the 20 restriction will not apply.
I trust that clarifies. It's really not difficult.
Not my work but taken from another group.
