It's simple, they don't want to get rid of them, because they don't want to be proved wrong. The road my parent's live on (Teehey Lane in Bebington) needs one because it's a 30mph road, but chavs constantly do 70mph down it.
On a 60mph road though? How about the offender do community service for two hours? Surely this would benefit more?
"C20 LET bang"