First, my apologies for taking so long to respond. I've been off Waze for a couple of months.
The Waze map is entirely maintained by Waze users, or such of them as want to help keep the map up to date. There is a tension between wanting all users to able to fix every problem they find, and wanting to keep the map working for drivers all the time, and therefore wanting to keep the mistakes that novice editors will inevitably make away from the main roads. There is a continual debate about how that balance should be made, and the only certain thing is we will never all agree that it is in the right place.
Waze has concepts of editor levels - basically the more experience the editor, the higher the level - and road "lock" levels, with the more important roads having a higher lock. You can't change a road with a lock level higher than your edit level.
If an editor wants to change a road which is locked over his/her level, they can post a new entry to this forum, and usually a senior editor will "downlock" the road. Or alternatively the senior editor may make the change himself.
Editors start off at level 1, and after a certain number of map edits, will automatically be "promoted" to level 2 and then eventually to level 3. Further promotions require both increased numbers of edits and the approval of the local senior editors.
More details of these and all other matters can be found on the "Wazeopedia" - here for the
general home page and here for
UK-specific guidance. Questions are probably best directed to the
UK forum.
For your specific case, when you know of changes from work, I think if you post to the
UK Editor Requests forum, somebody should unlock the road for you.
Happy Wazing,
Ian