Solving the critical need to upgrade our roads and bridges in large part through private investments as proposed in the Trump infrastructure plan does not begin to address the problem. Private investments can play a role in the solution, and they have done so for decades, but that role is severely limited. Toll roads and bridges will attract private investors, but they work only with heavy traffic flows where toll revenues are substantial. America's heavy travel corridors are already served by toll roads and toll bridges or by free Interstate highways. The greater need for investments is in maintenance and repair and additional roads and bridges in less dense areas. Private investments and toll revenues are not feasible in those instances. One possible way of raising finances for infrastructure is for a Congress to permit tolls on existing free Interstate highways, but I have yet to meet a politician with the courage to support that possibility.