Allow businesses or individuals the ability to enter into the transit system. This would help ensure that roads are no longer a tax draw that increases the price of gas, but a tax revenue maker. Let businesses buy stock into some major roads at both the federal and state level. Don't use traditional toll roads. A better system can use either GPS in license plates, or have small radio receivers inserted into license plates that can get signals at entrances and exits to roads.
Labor and repairs of these roads will be paid by those businesses or individuals. Protections against monopolies and price gouging can be ensured by the government. And non invested roads still government owned can be paid by a much lower gas tax. A lower gas tax will result in more travel and cheaper shipping.