That would resolve the issue and that is certainly what the tax has become.
Fuel Excise Duty is really an emission tax too.
I really get fed up with this pedentry. I regard both as Road Tax as does nearly everyone else. It is tax derived from using cars (with a few exceptions) on road. That and drink are two special preserves of the Exchequer for extorting money from a source that has almost no price elasticity. That's a blank cheque in taxese.
However, even those of us who have the odd Merlot or three, and well patronise our local hostelry do not expect the government to use that money to provide better drinking facilities. Or even that coke drinkers (aka drink tax evaders) should not be allowed in pubs. Oh, I think I just shot my own fox ...