There's a road here that's relatively modern as roads go.. it was built when I was a child to take traffic out of the centre. It's wide, straight and has no houses or anything along it that would attract pedestrians. It was clearly designed and built as a bypass.
The council recently made it 20.. I'm still scratching my head (a) why and (b) whether they really expect anyone to take any notice.
But then they'll leave a road as 30 and cover it with speed bumps.. including the main route to the motorway..