Nah, but I'm a driver so would say that, is frustrating as hell being kept to that speed when you can see no good reason, by al means stick them outside schools, heavy shopping areas, bad roads with accident history etc, but if everything is a 20 then nothing is 20 if you get me.
Safety often seems to be the only voice put forward, they never want to acknowledge the fact that people use roads for things and that they facilitate their employment and goods. How willing are they to pay more or earn less?
My other worry is the busybody, the disputant who just doesn't like traffic and will keep complaining, but the thing is if a council gives in and changes a road to a 20, that same person will often just start complaining again that it should be a 15, they would never be happy, I suspect a lot of these weird local schemes are essentially the result of one local pest who caught the MPs ear and just won't shut up.