windmill lane, in southall, has a 30 mph speed limit (for some reason, overnight EVERY road in southall with the postcode of UB1 or UB2 turned into a 30 mph or less limit, even the dual carriageways, theonly place that escaped was around 100 yards of the hayes by pass leading towards the M4 junction 3)

then, for all of about 5 yards, it's got a 40 mph limit going out of southall towards isleworth, then it goes under the M4 and it's a nsl road

but coming back towards southall, there is no 40 mph sign post, only a 30 mph one

how does that make sense?

one side of the road is 40 mph, the other side of the road is 30 mph, and it's a single carriageway B road