Section 13 of the Federal-Aid Highway Act of 1938 directed the Bureau of Public Roads to submit a feasibility study for a system of six cross-country superhighways (three running east-west and three running north-south), including the feasibility of toll systems on the roads. The 1939 report determined that toll funding would not work for transcontinental roads but the traffic and route studies in the report, and its master plan for free road development, laid the groundwork for the later development of the Interstate Highway System.