The roads are entirely different and were built on different pretenses by different people. There will never be any model like you described as long as the greenway is private. They are two separate toll roads that are abutted together. And people do complain about the Dulles Toll Road, because it's toll rates are climbing at astronomical rates, and are known to keep on that path because of the 'pass the buck' deal the State made with the airport authority to fund metro. Advocates for distance based tolls ignore that the company will never implement a model that would cause their revenues to go way down. Just because Ashburn is halfway down the toll road.. that doesn't mean your tolls would be cut in half. I could care less what the greenway charges... let them decide what their customers are willing to pay. But what is wrong is the state relying on the bypass as a main artery in the area.