464 ANNUAL EEPOKTS OF DEPAKTxMENT OF AGRICULTUEE. 



fiscal year, and other information specifically defined in the act 

 necessary for a full and comprehensive report of the activities under 

 the act during the preceding fiscal year. As all such information 

 will be set forth in complete detail in that report, there is indicated 

 in this report only a summary of the salient facts with reference to 

 the expenditure of Federal and State funds, the mileage of roads 

 completed during the fiscal year, and the aggregate of mileage com- 

 pleted since the initiation of the work by the Federal-aid road act, 

 approved July 11, 1916, together with a statement of the work under 

 construction at the close of the fiscal year. 



The second class of functions, those provided for by the act mak- 

 ing appropriations for the Department of Agriculture, involving 

 scientific research with respect to roads and agricultural engineering, 

 are covered in full in this report. 



FEDERAL AID ROAD WORK. 



Eight thousand eight hundred and twenty miles of roads of all 

 types were completed during the fiscal year, which, added to the 

 mileage completed prior to the fiscal year, brought the total of com- 

 pleted projects up to 26,536 miles. The mileage completed during 

 the year is classified as follows: 



Miles. 



Graded and drained 1,860.1 



Sand-clav 749.5 



Gravel 3,815.4 



Water-bound macadam 335.6 



Bituminous macadam 452.9 



Bituminous concrete 76.8 



Concrete 1,440.3 



Brick 78.8 



Bridges laS 



Total 8,820.2 



The projects under construction at the close of the year amounted 

 to 14,772 miles and w'ere estimated as 53 per cent complete. In addi- 

 tion to the 26,536 miles completed and the 14,772 miles under con- 

 struction, there were at the close of the year a number of projects 

 approved but not yet placed under construction, the aggregate length 

 of which was 6,917 miles. 



The total cost of the roads completed during the year was $148,- 

 152,528, of which $63,087,079 w^as paid bj^ the Federal Government. 



DESIGNATION OF THE FEDERAL-AID HIGHWAY SYSTEM. 



The work of selecting the roads to constitute the Federal-aid 

 highway system, begun during the preceding fiscal year, was con- 

 tinued with all possible expedition consistent with the far-reaching 

 importance of the decisions involved. By the close of the year 

 tentative systems had been submitted by the State highw^ay de- 

 partments or proposed by the Bureau of Public Roads for all States. 



As the result of conferences with officials of the several States 

 and groups of States, 35 of these systems had been definitely ap- 

 proved by the Secretary at the close of the fiscal year, and it was 

 anticipated that the svstems of the remaining States would be ap- 

 proved by the fall of 1923. 



The total mileage of highways existing in the United States at 

 the time of the passage of the Federal highway act (Nov. 9, 1921), 



