A regressive tax is a tax imposed so that the tax rate decreases as the amount to which the rate is applied increases

100 miles 10 Dollars, 200 miles 15 Dollars would be a regressive tax.
100 miles 10 Dollars, 200 miles 20 Dollars would be a proportional tax.
100 miles 10 Dollars, 200 miles 30 Dollars would be a progressive tax.

You seem to be against a regressive tax according to the above definition, Bobert? Good idea. Any good environmentalist should agree with you.

Or do you mean something completely different which has nothing to do with the definition of regressive tax as quoted above?

Wolfgang