Quite simply remove all these pointless, expensive and car damaging schemes, that includes road width reduction, speed humps and any other ridiculous ideas.
If your speeding have the police do what they are paid to enforce or cameras, just because some under endowed idiot speeds you cannot force the rest of the population to sit under draconian traffic calming schemes.
Murder is illegal, but you don't have the whole population using plastic cutlery just in case!.