System designers proposed exit routes for each city as well as bypasses to get around the rubble of war. In fact, the project was called the National Interstate Highway and Defense System, and at one point, ordinary passenger cars were not going to be allowed access. Only a cynic would claim that the defense argument was trumped up, even though for three years no one noticed that the bridges were too low to provide adequate clearance for military vehicles transport ing missiles. In a classic example of the conflicts between local and federal control, Congress and the various states argued both about who would pay to construct this massive public works project as well as about who would pay the maintenance costs. Even though sin ce 1918, the states and the federal government had shared the cost of road construction 50-50, the states argued that they needed those funds for local roads.
Maintenance falls to the states, and law enforcement on the highways is a state responsibility.
The arguments about the source of funds for highway maintenance and development were spirited. Some argued that the heaviest users should pay the highest tariff. B ut there is no toll gate on Interstate Highways. The location of on-ramps and interchanges was the key factor in economic development of many rural areas, and when the old state routes that usually went through small towns were no longer traveled, many communities became ghost towns. In addition, the b uilding project itself provided opportunities for manufacturing and construction.