The overwhelming probability is that you are going to get both a tax increase and toll roads. The toll road question arrives during a perfect storm of economic ignorance. The Democrats will oppose it because they think that the government, through government edict, can make anything affordable by wealth redistribution. The Republicans and the Libertarians will see toll roads as financially responsible. They will be focused on the triumph of the market place.

What everyone will fail to see is that the toll roads, operated at a profit, will become the new winners that must carry the hoards of losers that will continue to be spawned by TDOT and the legislature. The Libertarians will thus enable sub par management of non-toll highway infrastructure in Tennessee. The Socialist will eventually love the idea that the rich on the tollways are supporting the poor on the rest of the system. The rest of the economic illiterates will get the warm fuzzies thinking that the trucks are going to pay most of the taxes for the roads while they will pay practically nothing including at the cash registers of places where they buy things that have recently arrived on a truck. In Florida, the economic illiterates think the tourist pay for the toll roads so they did not bother to show up at the Suncoast Parkway and the tollway continues to be a financial failure.

The state gas tax is now below the inflation adjusted 2 cents that was first enacted in 1923. The legislature still does not realize that they can not have the immediate gratification of this century with the tax effort of the last century. Even if the state manages to hang on to the current gas tax for a year or two, the federal government may have to enact a gas tax increase in 2008 or 2009 to clear out the red ink in the federal highway trust fund. This will panic the Tennessee Legislature because the state gas tax income will be unable to match what the federal government will have to offer in the federal highway trust fund.

In 2005, TDOT operated the highways in Tennessee for 2.3 cents per vehicle mile traveled. On the Indiana Tollway, the cost per mile for two axle vehicles is 2.96 cents per mile, but for 7 axle trucks it is 31.39 cents per mile. The average toll is close to 6.2 cents per vehicle mile.

The main difference between a tollway and a state highway department is that the tollway can negotiate almost total isolation from legislative misbehavior.
Tolls can be adjusted to inflation and tolls can be optimized for income by discovering elasticity relationships. The state protects the toll operator from competition with non-toll alternatives. The state guarantees minimum rate of return, most of the time it is 12% or more. The state stipulates at the beginning exactly how much income is to be transferred away from the toll facility for non-related government activity or a lump sum up front payment.

Toll roads operated by companies, foreign or domestic, are not cash cows to be slaughtered at the leisure of the legislature, they are protected and pampered in a way that TDOT can only dream of. No business, including sports franchises, enjoy so much protection and so much deferential treatment. Your state pension fund will probably be invested in a toll road company.