They did not. They paid to have roads that were shared with other legal uses along with other taxpayers, some that are bicyclists. Motorists did pay for the interstate system that is theirs alone by law.The point you're missing (or willfully ignoring): the motorists already did pay to have their own roads.
You are claiming something that is counter to the laws. If you don’t like the laws there are ways to change them. Until that time bicycles have every equal right to use the roads…