i always thought that if any highway was built with federal monies, tolls could NOT be imposed. this is what happened in the state of Connecticut. the state put up toll plaza's, the feds made them take them down.
if however, any state can show good enough reason(s) to collect tolls for repairs, etc, maybe the fed's will give them this right to do so. its a changing economy/world, and we as either a nation, or group of people (truckers) will not be able to stop this from happening.