1429. Projects part of connected interstate system to have preference; States 7 per centum system; classes therein; approval of Secretary; increase of system mileage. That in approving projects to receive Federal aid under the provisions of this Act the Secretary of Agriculture shall give preference to such projects as will expedite the completion of an adequate and connected system of highways, interstate in character.

Before any projects are approved in any State, such State, through its State highway department, shall select or designate a system of highways not to exceed 7 per centum of the total highway mileage of such State as shown by the records of the State highway department at the time of the passage of this Act.

Upon this system all Federal-aid apportionments shall be expended.

Highways which may receive Federal aid shall be divided into two classes, one of which shall be known as primary or interstate highways, and shall not exceed three-sevenths of the total mileage which may receive Federal aid, and the other, which shall connect or correlate therewith and be known as secondary or intercounty highways, and shall consist of the remainder of the mileage which may receive Federal aid.

The Secretary of Agriculture shall have authority to approve in whole or in part the systems as designated or to require modifications or revisions thereof: Provided, That the States shall submit to the Secretary of Agriculture for his approval any proposed revisions of the designated systems of highways above provided for.

Not more than 60 per centum of all Federal aid allotted to any State shall be expended upon the primary or interstate highways until provision has been made for the improvement of the entire system of such highways: Provided, That with the approval of any State highway department the Secretary of Agriculture may approve the expenditure of more than 60 per centum of the Federal aid apportioned to such State upon the primary or interstate highways in such State.

The Secretary of Agriculture may approve projects submitted by the State highway departments prior to the selection, designation, and approval of the system of Federal-aid highways herein provided for if he may reasonably anticipate that such projects will become a part of such system.

Whenever provision has been made by any State for the completion and maintenance of 90 per centum of its system of primary or interstate and secondary or intercounty highways equal to 7 per centum of the total mileage of such State, as required by this Act, said State through its State highway department, by and with the approval of the Secretary of Agriculture, is hereby authorized to increase the mileage of the primary or interstate and secondary or intercounty systems by additional mileage equal to not more than 1 per centum of said total mileage of such State, and thereafter to make like increases in the mileage of said systems whenever provision has been made for the completion and maintenance of 90 per centum of the mileage of said systems previously authorized in accordance herewith. (Nov. 9, 1921, sec. 6, 42 Stat. 213; July 21, 1932, sec. 304, 47 Stat. 722; 23 U. S. C., sec. 6.)

1430. Conditions under which Federal aid may be given to more than 7 per centum of the State highway mileage.-The system of Federalaid highways on which Federal funds may be expended in any State may exceed 7 per centum of the total highway mileage of such State by the mileage of roads on said system within national forest, Indian, or other Federal reservations therein. (May 21, 1928, sec. 3, 45 Stat. 683; 23 U. S. C., sec. 6a.)

1431. Expenditure on highways within municipalities; construction of bridges within municipalities.-Federal funds may be expended on that portion of a highway or street within a municipality having a population of two thousand five hundred or more, along which from a point on the corporate limits inwardly the houses average more than two hundred feet apart: Provided, That no Federal funds shall be expended for the construction of any bridge within or partly within any municipality having a population of more than thirty thousand, as shown by the latest available Federal or State census; but this limitation shall not apply in the case of an interstate bridge, including approaches, connecting such municipality in one State with a point in an adjoining State which may be within a municipalty having a population of not more than ten thousand. (May 21, 1928, sec. 4, 45 Stat. 683; 23 U. S. C., sec. 6b.)

1432. Limitations upon highway construction and bridges within municipalities; payments per mile removed. The limitations in the Federal Highway Act, approved November 9, 1921, as amended and supplemented, upon highway construction, reconstruction, and bridges within municipalities and upon payments per mile which may be made from Federal funds, shall hereafter not apply. (June 18, 1934, sec. 13, 48 Stat. 995; 23 Ú. S. C., sec. 6c.)

1433. State to provide funds.-That before any project shall be approved by the Secretary of Agriculture for any State such State shall make provisions for State funds required each year of such States by this Act for construction, reconstruction, and maintenance of all Federal-aid highways within the State, which funds shall be under the direct control of the State highway department. (Nov. 9, 1921, sec. 7, 42 Stat. 214; 23 U. S. C., sec. 7.)

1434. Adequate construction materials required. That only such durable types of surface and kinds of materials shall be adopted for the construction and reconstruction of any highway which is a part of the primary or interstate and secondary or intercounty systems as will adequately meet the existing and probable future traffic needs and conditions thereon. The Secretary of Agriculture shall approve the types and width of construction and reconstruction and the character of improvement, repair, and maintenance in each case, consideration being given to the type and character which shall be best suited for each locality and to the probable character and extent of the future traffic. (Nov. 9, 1921, sec. 8, 42 Stat. 214; 23 U. S. C., sec. 8.)

1435. Freedom from tolls.-That all highways constructed or reconstructed under the provisions of this Act shall be free from tolls of all kinds. (Nov. 9, 1921, sec. 9, 42 Stat. 214; 23 U. S. C., sec. 9.) 1436. Federal aid for toll bridges.-That notwithstanding any provision of the Act entitled "An Act to provide that the United States shall aid the States in the construction of rural post roads, and for

other purposes", approved July 11, 1916, or of the Federal Highway Act, the Secretary of Agriculture may extend, on the same basis and in the same manner as in the construction of any free bridge, Federal aid under such Acts, in the construction of any toll bridge and approaches thereto, by any State or States, or political subdivision or subdivisions thereof, upon the condition that such bridge is owned and operated by such State or States, or political subdivision or subdivisions thereof, and that all tolls received from the operation thereof, less the actual cost of operation and maintenance, are applied to the repayment to the State or States, or political subdivision or subdivisions thereof, of its or their part of the cost of construction of such bridge, and upon the further condition that when the amount contributed by such State or States, or political subdivision or subdivisions thereof, in the construction of such bridge shall have been repaid from the tolls, the collection of tolls for the use of such bridge shall thereafter cease, and the same shall be maintained and operated as a free bridge. (Mar. 3, 1927, 44 Stat. 1398; 23 U. S. C., sec. 9a.)

1437. Requirement of Federal Highway Act as to freedom from tolls not applicable to publicly owned bridges.-That hereafter in the administration of the Federal Highway Act and Acts amendatory thereof or supplementary thereto, the first paragraph of section 9 of the Act of November 9, 1921 [23 U. S. C., sec. 9], shall not apply to publicly owned toll bridges or approaches thereto, constructed and operated by the highway department of any State, subject, however, to the condition that all tolls received from the operation of any such bridge, less the actual cost of operation and maintenance, shall be applied to the repayment of the cost of its construction, and when the cost of its construction shall have been repaid in full, such bridge thereafter shall be maintained and operated as a free bridge. (Mar. 3, 1933, 47 Stat. 1456; June 16, 1933, sec. 204 (g), 48 Stat. 204; 23 Ú. S. C., sec. 9b.)

1438. Minimum width of right-of-way and wearing surface prescribed. That all highways in the primary or interstate system constructed after the passage of this Act shall have a right-of-way of ample width and a wearing surface of an adequate width which shall not be less than eighteen feet, unless, in the opinion of the Secretary of Agriculture, it is rendered impracticable by physical conditions, excessive costs, probable traffic requirements, or legal obstacles. (Nov. 9, 1921, sec. 9, 42 Stat. 214; 23 U. S. C., sec. 10.)

1439. Planting and maintaining shade trees.-In every case in which in the judgment of the Secretary of Agriculture and the highway department of the State in question, it shall be practicable to plant and maintain shade trees along the highways authorized by said Act of November 9, 1921, and by this Act, the planting of such trees shall be included in the specifications provided in section 8 of said Act of November 9, 1921 [23 U. S. C., sec. 8]. (May 21, 1928, sec. 2, 45 Stat. 683; 23 U. S. C., sec. 10a.)

1440. Funds apportioned to States; when made available. That when any State shall have met the requirements of this Act, the Secretary of the Treasury, upon receipt of certification from the governor of such State to such effect, approved by the Secretary of Agriculture, shall immediately make available to such State, for the purpose set forth in this Act, the sum apportioned to such State

as herein provided. (Nov. 9, 1921, sec. 10, 42 Stat. 214; 23 U. S. C., sec. 11.)

1441. Submission of project statements; approval; setting aside share of Federal aid by Treasury Department; percentages of Federal share specified. That any State having complied with the provisions of this Act, and desiring to avail itself of the benefits thereof, shall by its State highway department submit to the Secretary of Agriculture project statements setting forth proposed construction or reconstruction of any primary or interstate, or secondary or intercounty highway therein. If the Secretary of Agriculture approve the project, the State highway department shall furnish to him such surveys, plans, specifications, and estimates therefor as he may require; items included for engineering, inspection, and unforeseen contingencies shall not exceed 10 per centum of the total estimated cost of its construction.

That when the Secretary of Agriculture approves such surveys, plans, specifications, and estimates, he shall notify the State highway department and immediately certify the fact to the Secretary of the Treasury. The Secretary of the Treasury shall thereupon set aside the share of the United States payable under this Act on account of such projects, which shall not exceed 50 per centum of the total estimated cost thereof, except that in the case of any State containing unappropriated public lands and nontaxable Indian lands, individual, and tribal, exceeding 5 per centum of the total area of all lands in the State, the share of the United States payable under this Act on account of such projects shall not exceed 50 per centum of the total estimated cost thereof plus a percentage of such estimated cost equal to one-half of the percentage which the area of the unappropriated public lands and nontaxable Indian lands, individual and tribal, in such State bears to the total area of such State: Provided, That the limitation of payments not to exceed $15,000 per mile, under existing law, which the Secretary of Agriculture may make be, and the same is hereby, increased in proportion to the increased percentage of Federal aid authorized by this section: Provided further, That these provisions relative to the public-land States shall apply to all unobligated or unmatched funds appropriated by the Federal Aid Act and payment for approved projects upon which actual building construction work had not begun on the 30th day of June 1921.

And provided further, That in the case of any State containing unappropriated public lands and nontaxable Indian lands, individual and tribal, exceeding 5 per centum of the total area of all lands in the State in which the population, as shown by the latest available Federal census, does not exceed ten per square mile of area, the Secretary of Agriculture, upon request from the State highway department of such State, may increase the share payable by the United States to any percentage up to and including the whole cost on projects on the primary system of Federal-aid highways and on projects on the secondary system when the latter is a continuation of a route on the primary system or directly connects with a route on the primary system of an adjoining State, but such State shall allocate and expend during the same fiscal year upon some other project or projects on the Federal-aid system, under the direction of the Secretary of Agriculture, the amount it would have been required to

expend upon such project. (Nov. 9, 1921, sec. 11, 42 Stat. 214; June 19, 1922, sec. 4, 42 Stat. 660; Feb. 12, 1925, sec. 4, 43 Stat. 890; May 21, 1928, 45 Stat. 683; 23 U. S. C., sec. 12.)

1442. Increase in amount of Federal aid per mile; conditions.-The limitation of payments which the Secretary of Agriculture may make is increased to $25,000 per mile, exclusive of the cost of bridges of more than twenty feet clear span; Provided, That the Federal participation shall be limited to $15,000 per mile until the original certified seven-percent system of such State shall have been surfaced: Provided further, That any such increase above $15,000 per mile shall be certified by the Director of the Bureau of Public Roads and the Secretary of Agriculture as securing actual extension of the highway system or economy in its construction: Provided further, That the limitation of payments herein provided shall apply to the public-land States, except that the same is hereby increased in proportion to the increased percentage of Federal aid authorized by section 11 of the Act entitled "An Act to amend the Act entitled 'An Act to provide that the United States shall aid the States in the construction of rural post roads, and for other purposes, approved July 11, 1916, as amended and supplemented, and for other purposes approved November 9, 1921, as amended [23 U. S. C., sec. 12]. The provisions of this section relating to the limitation of payments per mile which the Secretary of Agriculture may make shall apply to all funds heretofore appropriated and available for payment to the States on the date of approval of this amendatory Act and to all sums hereafter appropriated for carrying out the provisions of such Act of July 11, 1916, as amended and supplemented [23 U. S. C., sec. 12]. (Apr. 4, 1930, sec. 3, 46 Stat. 141; 23 U. S. C., sec. 12a.)

1443. Construction and reconstruction.-That the construction and reconstruction of the highways or parts of highways under the provisions of this Act, and all contracts, plans, specifications, and estimates relating thereto, shall be undertaken by the State highway departments subject to the approval of the Secretary of Agriculture. The construction and reconstruction work and labor in each State shall be done in accordance with its laws and under the direct supervision of the State highway department, subject to the inspection and approval of the Secretary of Agriculture and in accordance with the rules and regulations pursuant to this Act. (Nov. 9, 1921, sec. 12, 42 Stat. 215; 23 U. S. C., sec. 13.)

1444. Payment to State; time and manner of making.-That when the Secretary of Agriculture shall find that any project approved by him has been constructed or reconstructed in compliance with said plans and specifications, he shall cause to be paid to the proper authorities of said State the amount set aside for said project.

That the Secretary of Agriculture may, in his discretion, from time to time, make payments on such construction or reconstruction as the work progresses, but these payments, including previous payments, if any, shall not be more than the United States pro rata part of the value of the labor and materials which have been actually put into such construction or reconstruction in conformity to said plans and specifications. The Secretary of Agriculture and the State highway department of each State may jointly determine at what time