okay, I'm going to mentally picture (and tell you all about it) the road I used to travel every day into town (before I moved)
It's NSL the entire 5 miles, except for the last bit where you get into the town.
Leave home. turn left onto "main" road - straight road where I can go flat out (60mph)until the hill before the junction.
slow right down, turn right.
go at about 30ish until the trees, slow right down again, and stay slow even though road widens out because school is just there.
then go even slower as road narrows (interestingly, there is a SLOW written on the road, but it faces in the opposite direction from the narrow bit - it's aimed at the school, not the narrowness)
then drive considerately (25-30ish) through the village until the church.
slow to 15.
speed up again after the bungalow, and stay fastish until after the farm (because it's the motorway bridge and the road is really wide and straight)
slow down past the pub (narrow again) until after the farmhouse.
speed up a bit.
hill (where after a rainy night, it's v-e-r-y s-l-o-w because the road floods)
slow.
round bend, down hill, slow
valley, drive at 30ish, long road, but with slight bend like a ( all the way down.
round to the quarry, speed up.
then slow down going into the trees because a man was knocked down at twilight on this stretch.
stay slow to the top of the hill, where the road becomes a massive blind bend (the bend >>> arrows have been knocked down)
go past the farm, bit faster, but not much (say 30 again) until the junction, which has changed priority and is a bit weird.
30mph zone.
So, I've just driven almost 5 miles along roads that are NSL, but I have done less than 30 for most of it, apart from about (total 600 yards at 60, and about another 1000 yards at 40mph.