DISTRIBUTION IN RELATION TO GEOGRAPHY AND POPULATION
The second consideration was that the routes chosen should be reasonably distributed geographically and in relation to the distribution of the population of the country; that, consistent with other requirements, they should pass through as many States as possible. Accordingly the northern east–west route clings to the northern tier of States from New England to Washington. The southern east–west route traverses the southern tier. The central east–west route passes almost exactly through the center of the country. The eastern and western north–south routes approximately parallel the coasts, and the central north-south route, though for valid reasons it departs somewhat from a central position geographically, intersects the central east-west route close to the center of population. The 6 major routes and 3 diagonal branches traverse for some distance 41 of the 48 States.
ACCORD WITH POPULAR TRAVEL ROUTES
A third consideration in the selection of the routes was that they should accord reasonably with recognized popular routes of travel. For their movements across the country, whether the distances were long or short, motorists have previously had a considerable choice of routes, between which, in the beginning at least, there was little advantage of improvement. By their choice, as reflected in the relative density of present traffic on various highways, they have established certain preferred routes, which stand out quite clearly as the widest bands on a traffic map of the country. (See pl. 8.) In the selection of routes for the superhighways close conformity to these preferred lines of travel was an important objective. This consideration weighed heavily in the decision to include the two western branches of the central route among those to be investigated. These branches, one coinciding closely with the historic Dee Trail and the other with the pioneer movement of the Mormons into southern Utah, both bear the stamp of approval of the early pathfinders and a long succession of their followers.
This consideration also strongly influenced the southwestward slant of the central north-south route, which follows closely a line selected by many travelers for winter use in driving from the populous Northeast to the Pacific coast.
IMPORTANT TERMINI AND REASONABLY DIRECT COURSE
A further consideration was that the several routes should have important continental termini and should run as directly between these ultimate objectives as might prove to be consistent with the connection of important intermediate points and the development of traffic. It is believed that the routes selected fulfill these requirements.
The eastern north-south route joins the New England and Florida playgrounds, and passes within a reasonable distance of all the coastal cities. The central north-south route has its termini at the international bridges at Port Huron, Mich., and Laredo, Tex. At the south it is the logical connection with the Inter-American Highway. For 157 miles in the north it joins with the northern east-west route,
