Penn State University Assistant Professor Peter Swan and Michael Belzer of Wayne State University used federal and Ohio Turnpike data to conclude that if governments allow private toll road operators to maximize profits, higher tolls will divert trucks to local roads -- and that is important for economic and social reasons.

The researchers said many substitute, toll-free roads are two-lane highways with crash rates many times that of a turnpike. And increased traffic along such routes reduces the quality of life for communities located along diversion routes, as well as dramatically increasing road maintenance costs.

"If the true problem is that political leaders are unwilling to face the voters with the reality that there is no free lunch, then the problem we seek to solve by tolling and privatization will not solve the problem at all. In fact, our research suggests that it will only make the problem worse," Swan and Belzer said.

The study was presented Monday in Washington during the annual meeting of the Transportation Research Board.