Federal Aid Highway Act of 1938
In both 1921 and 1935, the executive department did comprehensive studies of U.S. highways and their suitability for meeting current defense needs. Also during the Great Depression, a joint study by the War Department and Department of Agriculture's Bureau of Public Roads looked at road improvements for national defense and economic development.
The 1938 Act authorized a study for six superhighways: three east-west routes and three north-south routes. The study "Toll Roads and Free Roads" found that all six routes were feasible from the engineering point of view but, as some of these routes were planned as toll roads, the study found that some of the routes would be economically infeasible: toll revenues would not meet projected costs for maintenance and expansion. Also, considering the general lack of funds in 1938, the legal problems of creating interstate highway standards, and the federal government's traditional reluctance to aid state or local internal improvements cast a rather doubtful conclusion on the probability of constructing a nationwide system of super-highways. The report is more significant for being a master plan for interstate construction than as a 1930s highway plan.