Page:Highways for the National Defense.pdf/42

Rh Between these two extremes of roads-those seriously inadequate and those in the main fully adequate- there are, on the basis of traffic volume, 10,374 miles of the rural network with adequate pavement widths and 43,120 miles with inadequate widths. This latter mileage and the 5,090 miles with pavement less than 18 feet wide make a total of 48,210 miles of roads in the entire rural network, as shown by table 7, with existing surfaces inferior in width to the standards prescribed.

Of this 48,210 miles of inferior roads, 18,887 are included in the proposed interregional system and constitute 73.9 percent of its total mileage; and 29,323 miles are outside the interregional system and form 71.0 percent of the total mileage of all other roads in the strategic network.

As table 7 shows, the extremity of inadequacy is reached on 1,037 miles of the network on whcih existing surfaces less than 18 feet wide are subjected to traffic averaging more than 1,800 vehicles per day. Of this extremely inadequate mileage, 361 miles are included in the interregional system. On the entire mileage, the prescribed standards call for 24-foot pavements.