The city streets over which the urban mileage included in the recommended interregional system has been measured, are those now marked as the transcity connections of the existing main rural highways that conform closely to the rural sections of the recommended routes. These streets generally pass through or very close to the existing central business areas of the cities.
The total milage of these streets in cities of 10,000 or more population has been classified with respect to the use of the land in the areas they traverse. This classification shows that 10.5 percent of the mileage lies within the central business areas of the cities.
In reaching the central sections, these streets pass through several other classes of development, and the percentage of mileage within areas of each class is shown in table 15. As will be seen from this table, approximately 7.5 percent of the length of these existing streets in cities of 10,000 or more population is located in areas classified as industrial, 12.2 percent in outlying business areas, 24.3 percent in areas described as mixed business and residential, 23.8 percent in residential areas, 14.7 percent in areas of scattered development, 3.4 percent in park or other municipally owned areas, and 3. 6 percent in areas of other description.
As a further indication of the character of these traversed areas, table 15 also shows those wholly or partially devoted to residence, classified as high, intermediate, and low class. The greater part of the mileage falls in what are described as areas of intermediate class.
Since it is probable that in any development of the interregional routes, the locations chosen will not follow the streets presently used in many cases, the percentages and detailed data given in table 15 can be considered as only generally indicative of the Jand uses in the areas that will be traversed, and of the nature of land-acquisition problems involved in the development.
Location internally through wedges of undeveloped land.—As previously pointed out, the improvement of highways at urban centers has in the past stimulated outward extension of city growth, and has left wedges of relatively undeveloped land between these ribbons of development along the main highways entering the city. To some extent these wedges are the result of a topography less favorable for development or of the reservation of land for various public uses. In most cases they are caused in part by the lack of satisfactory connection with the city, either by roads of direct entrance or by appropriate transverse connection with the main highways.
Whatever their cause, existing wedges of vacant land may offer the best possible locations for city-entering routes of the interregional system. Alinement and right-of-way widths appropriate for the new highways and difficult of acquisition in more developed areas, may be obtainable in these vacant spaces with relative ease and at moderately low cost. So placed, the routes may often be extended far into the city before they encounter the greater difficulties of urban location.
In choosing these locations for the arterial routes, however, it should be recognized that the undeveloped lands which lie so favorably for highway purposes also present opportunities equally favorable for other purposes of city planning. Properly preserved and developed, they can become the needed parks and playgrounds for residents of adjacent populated areas. Alternatively, they can be developed as new residential communities in the modern manner, unhampered by
