John MacDonald: My one reservation about universal road charges

I bet if you drive a petrol vehicle and you’ve said anything about how much cheaper it must be to have a diesel, anyone who does have a diesel has jumped down your throat and started banging-on about road user charges. Or RUCs, as they’re known.

Because when you buy petrol you pay a fuel tax. When you buy diesel, you don’t. But you have to —or you’re supposed to— pay road user charges.