Shows National Park--to--Park highways, Associated Tours highways, and main traveled highways. Also shows Indian reservations and national parks, monuments, forests, and irrigation projects.; Includes index to named highways, text, and illus.The National Highways Association (NHA) was established in 1911 to promote the development of an improved national road network in the United States. Under the slogan “Good roads for everyone!” the NHA advocated the building and permanent maintenance by the federal government of a system of 50,000 miles (some 80,500 kilometers) of highways. This system was to be composed of six main national highways, 13 trunk national highways, and 40 link highways. The link highways, the NHA explained, would connect “...