One more stab at 20mph

Just from the Areley Kings blog regarding the wonderful news about 20mph zones. [Sigh] my points are made in the comment, but it just irks me when anyone does a 'it's great we've got this as it means this' when it doesn't. I'm talking about the switchback between Stourport and Bewdley - it's a derestricted road; except I shouldn't be calling it that, it's a National Speed Limit Applies road.

What that means is that as it is a single unlit lane the maximum speed for most vehicles is 60mph. On the blog we get a 'great now it can be a 50mph' except there was no reason it couldn't have been anyway.

See a restricted road has a maximum speed of 30mph. To keep things simply a restricted road is a lit road, that's why you don't need 30mph repeater markers if you see lampposts, you have to assume it's a 30; everywhere else is a National Speed Limit Applies.

Yet it's possible to see lit roads at 40mph and unlit roads at 50mph or even 40mph; so why is that the switchback can 'suddenly' become a 50mph when this has been possible for quite some time?