Shoutbox

I think in the US it's either that one doesnt pay road tax, and the tolls act as road tax, therefore you pay more depending on how much road you use.

Or that you only pay tax when you cross the state line.

The M6 Toll was made for entirely different reasons, the idea is that it eases a lot of traffic of the heavily congested M6. If it was free then it wouldnt really make much of a difference traffic wise. Since te M6 Toll is not a neccessary road, it isnt paid for by the road tax