BUREAU OF PUBLIC EOADS. 497 



15 and 17 per cent, respectively, of the whole mileage of Federal-aid 

 roads. In thus referring to the mileage of our roads which is included 

 in these selected routes, it is not intended to convey the impression 

 that such routes constitute a desirable or complete system of national 

 roads. Indeed, it is safe to say that no one of such roads is laid down 

 at all points in the most suitable location. In many instances we 

 believe that sections of our roads which do not fall on the lines of these 

 routes, will better serA^e the transcontinental traveller than the 

 selected routes, but in the main these widely advertised roads do 

 follow the natural lines of travel. 



In order to provide a more rational basis for coordinated work on 

 the part of the States, the bureau, in conference with the advisory 

 committee of State highway officials, has initiated plans for a Nation- 

 wide survey of the roads of the country, and a classification of all 

 highways in respect to their importance and character of service. 

 The survey when completed will doubtless furnish the necessary data 

 for the establishment of a classified system of highwa3's similar to the 

 French system. 



Already the bureau is cooperating \vith the War Plans Division of 

 the General Staff and the Corps of Engineers of the War Department 

 in a stud}^ the purpose of wliich is the selection of those highways 

 which are important from a military standpoint, though at the outset 

 it is recognized that the highways which are required for commerce 

 and national development are in general identical with those required 

 for military purposes. This work, which has been imdertaken by 

 the War Department at the suggestion of the bureau, is being assisted 

 in evary way possible. The detaih d studies arc being conducted 

 by the department commanders, and the bureau is supplying maps 

 and n'^cessary information rela'iv^ to highways under consideration. 



The recommendations of the several department commanders will 

 be coordinated under the direction of the General Staff and fui-nished 

 to the bm-eau as a complete report covering the highways of impor- 

 tance from a military standpoint in the United States. When received 

 the recommendations in this report will be given careful consideration 

 and will be taken up in conferences with tne State highw^ay depart- 

 ments with a view to expediting the improvement of these highways 

 as a part of the Federal-aid progi-am. 



The requirement of the act that the construction of Federal-aid 

 roads must be of a substantial type must apply with equal force in 

 the desert of Nevada and the densely populated areas of New England, 

 New York, and Pennsylvania. In considering types of construction 

 which may be approved for Federal aid it has been impossible to apply 

 fixed and definite standards })ecause no standards can be found wliicn 

 will meet the variety of conditions presented throughout the country. 



Without, therefore, setting up definite requirements of construction 

 or stipulating that roads of a certain type or types only shall be con- 

 structed, it has been necessary to apply more fundamental considera- 

 tions to determine the adequacy of roads jn-oposcd l)y the Stat(^s as 

 Federal-aid projects. The consid(u-ations apj^lied in determining 

 whether a particular project is adofpiato and of a substantial typo 

 may be grouped under four gcincral clusses. 



The first class rc''ers to trallic, and under tliis heading each i)roject 

 is considered with respect to - 



(a) The amount of traflic at present using the road. 



