I live on a main road into a 65,000 population town. It's fully closed for three months, with only a single parallel back lane, full of parked cars, as a diversion - the signs as you enter, half a mile before the closure, say Road Ahead Closed, fair enough - but the Businesses Open As Usual sign is perhaps a bit misleading, as they're all beyond the closure. I get eight to ten artics a day trying to turn here now, having thought they might be able to get as far as they need to. Nobody's hit anything yet, but statistics will prevail at some point, I fear.
There is a 'beautiful' permanent sign on the A55 near Bangor - Width Limit 12 Miles Ahead - but no idea of what the limit will actually be when you get there.