United States Public Roads Administration

“ As a result there are few roads today where the space between the pavement and ditch or edge of fill is sufficient to insure the safety of parked vehicles and the traffic moving by them.
Entirely apart from considerations of defense usage, adequate provision for normal civil traffic on the more heavily traveled routes will require in the future a rather general widening of existing shoulders. But the possibility of more or less frequent use of a substantial part of the strategic network by motorized and mechanized Army convoys adds another important reason for building wider shoulders. ”

“ In each of these fields of operation the defense program of the United States is generating large amounts and varieties of highway traffic which demand new roads and new bridges. Indicative of the universal service of highway transport, many of the most pressing new highways or bridges are to serve essential requirements of the shore establishments of the Navy. ”

“ It does not appear to be practicable, in any reasonably highway program, to strengthen all the lightly surfaced local roads in all areas that might be used for battle practice. Moreover, even if it were practicable, such strengthening of all road surfaces would not be desirable from the standpoint of troop training. Actual battlefields cannot always be chosen in advance, and roads that are not of the best must sometime be encountered by armies in combat. ”

“ From the standpoint of the national-defense effort, the objective in access road construction is to provide adequate highway connections for the reservations and industrial areas with nearby main highways and railroads or other transportation services, and from neighboring towns and cities. From the standpoint of highway traffic, the developments planned at nearly all of the reservations and new industrial sites will be equivalent in their generation of highway traffic to the creation of a considerable number of new cities of very substantial size. ”

“ The Federal-aid, and the major exclusively State-highway programs have developed simultaneously with this rapid growth in the numbers and use of the motor vehicle.
In building roads to serve the expanding needs of the resulting traffic, the extensive mileage requiring improvement and the relatively limited funds available have at all times prevented the adoption of standards superior to those required by the currently realized or immediately expected traffic. These two considerations have instead generally forced the adoption of “stage construction” as a practical expedient. ”

“ The effort of the Public Roads Administration in this report is to present the necessary highway program as determined in detail by the three major defense agencies. The suggested division of costs is based upon the principle of major use. The access roads, as to the traffic to be served or as to their priority, are in the main requirements of the defense program. The development of the strategic network is very largely required by civil traffic, but the potential defense needs will advance the priority of many projects. ”

“ The recommended design standards for military usage are discussed in detail for the purpose of estimating the present adequacy of roads certified as important to the national defense, locating definitely the places at which improvements are desirable, and determining the character and costs of such improvements. Roads and bridges conforming in their design to these standards will generally be completely adequate for the service of both the normal civil and extraordinary defense needs. ”

“ Tactical roads of the third group may lie in areas used only once or repeatedly as the theater of maneuvers. For repeated use, it would appear desirable that they be fitted for their expected military use where only a single use is anticipated, or in any case where timely provision for strengthening of the weaker roads at Federal expense is not possible, there should be an alternative assumption of responsibility for any road damage that may be caused. ”

“ The design requirements as to structural capacity of bridges and standard pavements which have been applied to Federal-aid projects are consistent with the minimum requirements approved by the War Plans Division. Through the years there have been frequent criticisms that the Federal-aid policies required unnecessarily high standards. An adequately improved road system for a State or a nation is the product of long years of construction effort and the expenditure of vast sums. ”

“ Considering the utility of the highways and streets as a whole, exclusive of those specifically designated as defense highways, the normal maintenance operations and a program of replacements of worn-out and inadequate surfaces, perhaps below a normal construction program but none the less an irreducible minimum, are essential. ”

“ Strategic network.—By formal certification, the Secretaries of War and of the Navy have 'advised the Public Roads and Work Projects Administrations that projects for the improvement of any roads conforming to the approved strategic network are important to national defense. These certifications enable the Federal Works Administration to invoke for such projects the exceptional provisions of the Federal Highway Act of 1940 and the Emergency Relief Appropriation Act, fiscal year 1941, that apply to projects of importance to national defense. ”

“ In approving Federal-aid highway projects to be carried out with any unobligated funds apportioned to any State, the Commissioner of Public Roads may give priority of approval to, and expedite the construction of, projects that are recommended by the appropriate Federal defense agency as important to the national defense. ”

“ Roads of the first and second groups, and their bridges, will have to be made adequate for the expected military use. They will have to be designed to support frequent loads of military vehicles and equipment, with sufficient capacity to permit such frequent movements to occur without unreasonable interference with normal civil traffic. In respect to these first two groups of tactical roads, the urgency of improvement is substantially the same as that of access roads. ”

“ Since, in its main lines at least, the strategic network is heavily used by civil traffic, and since purely military traffic imposes few if any highway requirements superior to those required for the adequate accommodation of civil traffic, it follows that almost any improvement that may be made to facilitate movement of traffic will be serviceable to an important civil-traffic stream as well as to military movements and defense traffic. ”

“ The powers and duties of agencies dealing with highways in the national parks or in military or naval reservations under the control of the United States Army or Navy, or with highways used principally for military or naval purposes, shall not be taken over by the Secretary of Agriculture, but such highways shall remain under the control and jurisdiction of such agencies. ”

“ Military traffic was observed to have about the same effects as ordinary civil traffic, and the damage done during maneuvers was in all probability no greater than would have resulted from an equally intensive use by civil traffic. ”

“ Access roads.—The required program of access road improvement is highly dynamic. Indicated needs are growing from day to day as the general defense program matures.
Some of the military and naval reservations and defense industries are being newly established on land previously occupied by very small populations. Many are being substantially enlarged. Practically all are being greatly expanded in population and in motor transport and mechanized equipment facilities. ”

“ However, because of inherent financial difficulties and legal restrictions, only a part of the needed improvement can be effected by these means. Many of the larger and most vital projects require contractors’ organizations and extensive equipment for time-saving, efficient construction; and it is abundantly clear that the funds now available will be inadequate to effect all of even the most urgently required construction. ”

“ Required improvements range from the resurfacing and widening of two-lane roads to the construction of multiple-lane highways and large bridges, all of which should be completed in 1 year or less, if possible.
Tactical roads.—To a limited extent a considerable part of the highway mileage of the country, especially that part included in the strategic network, will be employed by the Army from time to time in tactical maneuvers to test and practice the use of its vast new motorized and mechanized equipment. ”

“ The strength of existing road surfaces approaches the desirable standard more nearly than their width. It has not been possible to determine with great accuracy the strength of all surfaces; but the facts available regarding their general type indicate that not more than about 14,000 miles of the rural network are incapable of supporting 9,000-pound wheel loads on pneumatic tires the year round. In very large part the surfaces deficient in strength arc also deficient in width and other qualities. ”

“ Its use must always be modified by a reasonable regard for the primary purpose of the appropriation, which is to provide work relief for as many as possible of the unemployed. It cannot be used at all in any area except as the relief rolls afford an available supply of labor. Nor can it be used for any purpose except as that purpose is sponsored by some qualified and acceptable agency. Projects for road improvement within Army and Navy reservations may be sponsored by military and naval authorities. ”

“ As previously stated, th e appropriations to the War and Navy Departments are not generally available for expenditure on roads outside of the boundaries of military and naval reservations.
Funds made available under the Federal Highway Act are of three classes: (1) Funds authorized for improvements on the Federal-aid highway system; (2) funds authorized for the construction of secondary or feeder roads; and (3) funds authorized for the elimination of hazards at railroad grade crossings. ”

“ Two-lane pavement width.—Existing two-lane roads having a pavement width of less than 18 feet, should be widened as promptly as possible.
Newly constructed and widened pavements on two-lane roads should be designed according to the following schedule of widths corresponding to various classes of present average 24-hour traffic volume:
The widths specified are substantially adequate for all normal civil traffic, including the usual percentages of wide and heavy vehicles, with range of speed from 15 to 70 miles per hour. ”

“ The lane loadings or standard trucks shall be assumed to occupy traffic lanes, each having a width of 10 feet corresponding to the standard truck clearance width. Within the curb-to-curb width of the roadway, the traffic lanes shall be assumed to occupy any position which will produce the maximum stress, but which will not involve overlapping of adjacent lanes, nor place the center of the lane less than 5 feet from the roadway face of the curb. ”

“ Under this policy, initial improvements have often been designed to meet only the imperative requirements of the realized traffic. More adequate improvements have been delayed by sheer necessity. Roads previously unimproved have been partially improved by grading and drainage, with surfacing deferred until a later date. Narrow surfaces have been built where it was definitely anticipated that later widening would be required. ”

“ Many of the roads of this class are little used by traffic of any kind, and are presently provided only with surfaces and structures consistent with such light usage. To prevent or repair damage by military movements in maneuvers and war games, substantial improvements will be needed, and must be charged almost wholly to defense. ”

“ Excessive curvature and inadequate sight distances are among the more common defects of existing improvements. Perhaps the most common defect is a general lack of shoulders of sufficient width to accommodate standing vehicles. The construction of narrow shoulders has been considered in the past a permissible cost-saving expedient. ”

“ Within the usually assumed tolerance of overloads, bridges of design and condition capable of supporting H–15 loading will safely support the loads of all commonly used commercial vehicles in the frequency with which they are normally applied. They will also similarly support the loads of all military equipment other than heavy and medium tanks, without special control of the movement. Load diagrams of the principal types of military equipment are shown in Plates 9 and 10. [1] ”

“ Initial thin surfaces have been constructed with the intention later of superimposing thicker or more durable surfaces. Existing weak and narrow bridges too costly to replace at once have been retained as long as possible, with safeguards to permit continued use without excessive hazard . ”

“ Following submission of the lists of posts and stations to the two branches of the Federal Works Agency, the War Department, on November 2, 1940, instructed its several corps area commanders to arrange local conferences to consider the access-road necessities of each of the listed posts and stations. ”

“ A majority of the reconnaissance studies were made prior to the passage of the selective-service and National Guard mobilization acts. Some of the conditions originally assumed have therefore been altered, and the improvements recommended in the reports are now subject to revision. ”

“ This table also shows the average gross weight of the heaviest vehicles passing over the bridges of each capacity class with an average frequency of 1 a day, and indicates the large degree to which some of the structures are overloaded by normal civil traffic. ”