[slavik81]

Why tax people per mile driven? Just put the tax on the gasoline (the actual source of the carbon) and you'll promote both driving less and fuel efficient vehicles. Whenever possible, design laws that promote the end result you want, not some proxy.

Of course, as much sense as it would make, raising the tax on gasoline is politically impossible. As is imposing a tax on miles driven.

The problem with making things directly visible to consumers is that everyone is a consumer and if the laws are annoying or harmful to them, they will vote in a government that repeals the laws. Then your carbon reduction measures are gone.