Title 23HighwaysRelease 119-73

§320 Bridges on Federal dams

Title 23 › Chapter CHAPTER 3— - GENERAL PROVISIONS › § 320

Last updated Apr 6, 2026|Official source

Summary

Federal agencies that own or control a dam on or after July 29, 1946 are allowed to design and build the dam so it can support a public highway bridge, and to build that bridge on the dam. The State highway department where the dam is located must first say the bridge is needed and cost‑effective and must ask the agency to make the dam and bridge. The agency in charge of the dam must decide the bridge is safe and will not harm dam operations. No bridge work can start until the State or local government agrees to build and keep the approach roads that connect the bridge to public highways. The federal agency can give needed easements or rights to land at no cost. The bridge built on the dam stays part of the dam and is kept up by the federal agency, and the agency can close it only for emergencies or national security. All extra costs for making the dam and bridge must be kept separate from other agency programs. Up to $65,000,000 is available for the Secretary to use as a fund to reimburse agencies for those extra costs, and more money can be appropriated later to pay back the fund. The part of a bridge inside the dam’s physical structure may be paid for entirely with federal money; the Secretary decides any extra federal share. The rest of the bridge and the approach roads must be paid for by the State or local government, but the dam agency still designs and builds the whole bridge and should follow the Secretary’s highway design guidance. “Agency” here means executive departments and other federal bodies that have custody of dams.

Full Legal Text

Title 23, §320

Highways — Source: USLM XML via OLRC

(a)Each executive department, independent establishment, office, board, bureau, commission, authority, administration, corporation wholly owned or controlled by the United States, or other agency of the Government of the United States, hereinafter collectively and individually referred to as “agency”, which on or after July 29, 1946, has jurisdiction over and custody of any dam constructed or to be constructed and owned by or for the United States, is authorized, with any funds available to it, to design and construct any such dam in such manner that it will constitute and serve as a suitable and adequate foundation to support a public highway bridge upon and across such dam, and to design and construct upon the foundation thus provided a public highway bridge upon and across such dam. The highway department of the State in which such dam shall be located, jointly with the Secretary, shall first determine and certify to such agency that such bridge is economically desirable and needed as a link in the State or Federal-aid highway systems, and shall request such agency to design and construct such dam so that it will serve as a suitable and adequate foundation for a public highway bridge and to design and construct such public highway bridge upon and across such dam, and shall agree to reimburse such agency pursuant to subsection (d) of this section for any additional costs which it may be required to incur because of the design and construction of such dam so that it will serve as a foundation for a public highway bridge and for expenditures which it may find it necessary to make in designing and constructing such public highway bridge upon and across such dam. In no case shall the design and construction of a bridge upon and across such dam be undertaken hereunder except by the agency having jurisdiction over and custody of the dam, acting directly or through contractors employed by it, and after such agency shall determine that it will be structurally feasible and will not interfere with the proper functioning and operation of the dam.
(b)Construction of any bridge upon and across any dam pursuant to this section shall not be commenced unless and until the State in which such bridge is to be located, or the appropriate subdivision of such State, shall enter into an agreement with such agency and with the Secretary to construct, or cause to be constructed, with or without the aid of Federal funds, the approach roads necessary to connect such bridge with existing public highways and to maintain, or cause to be maintained, such approach roads from and after their completion. Such agreement may also provide for the design and construction of such bridge upon and across the dam by such agency of the United States and for reimbursing such agency the costs incurred by it in the design and construction of the bridge as provided in subsection (d) of this section. Any such agency is hereby authorized to convey to the State, or to the appropriate subdivision thereof, without costs, such easements and rights-of-way in its custody or over lands of the United States in its custody and control as may be necessary, convenient, or proper for the location, construction, and maintenance of the approach roads referred to in this section including such roadside parks or recreational areas of limited size as may be deemed necessary for the accommodation of the traveling public. Any bridge constructed pursuant to this section upon and across a dam in the custody and jurisdiction of any agency of the United States, including such portion thereof, if any, as may extend beyond the physical limits of the dam, shall constitute and remain a part of said dam and be maintained by the agency. Any such agency may enter into any such contracts and agreements with the State or its subdivisions respecting public use of any bridge so located and constructed as may be deemed appropriate, but no such bridge shall be closed to public use by the agency except in cases of emergency or when deemed necessary in the interest of national security.
(c)All costs and expenses incurred and expenditures made by any agency in the exercise of the powers and authority conferred by this section (but not including any costs, expenses, or expenditures which would have been required in any event to satisfy a legal road or bridge relocation obligation or to meet operating or other agency needs) shall be recorded and kept separate and apart from the other costs, expenses, and expenditures of such agency, and no portion thereof shall be charged or allocated to flood control, navigation, irrigation, fertilizer production, the national defense, the development of power, or other program, purpose, or function of such agency.
(d)Not to exceed $65,000,000 of any money heretofore or hereafter appropriated for expenditure in accordance with the provisions of this title or prior Acts shall be available for expenditure by the Secretary in accordance with the provisions of this section, as an emergency fund, to reimburse any agency for any additional costs or expenditures which it may be required to incur because of the design and construction of any such dam so that it will constitute and serve as a foundation for a public highway bridge upon and across such dam and to reimburse any such agency for any costs, expenses, or expenditures which it may be required to make in designing and constructing any such bridge upon and across a dam in accordance with the provisions of this section, except such costs, expenses, or expenditures as would have been required of such agency in any event to satisfy a legal obligation to relocate a highway or bridge or to meet operating or other agency needs, and there is authorized to be appropriated any sum or sums necessary to reimburse the funds so expended by the Secretary from time to time under the authority of this section. Of each bridge constructed upon and across a dam under the provisions of this section, there may be financed wholly with Federal funds that portion thereof which is located within the physical limits of the masonry structure, or structures, of the dam, and the Secretary shall in his sole discretion determine what additional portion of the bridge, if any, may be so financed, such determination to be final and conclusive. The remainder of the bridge, and any necessary related approach roads, shall be financed by the State or its appropriate subdivision with or without the aid of Federal funds; but said portion of the bridge so financed by the State or its subdivisions, including such portion thereof, if any, as may extend beyond the physical limits of the dam, shall nevertheless be designed and constructed solely by the agency having custody and jurisdiction of the dam as provided in subsection (a) of this section.
(e)In making, reviewing, or approving the design of any bridge or approach structure to be constructed under this section, the agency shall, in matters relating to roadway design, loadings, clearances and widths, and traffic safeguards, give full consideration to and be guided by the standards and advice of the Secretary.
(f)The authority conferred by this section shall be in addition to and not in limitation of authority conferred upon any agency by any other law, and nothing in this section contained shall affect or be deemed to relate to any bridge, approach structure, or highway constructed or to be constructed by any such agency in furtherance of its lawful purposes and requirements or to satisfy a legal obligation incurred independently of this section.

Legislative History

Notes & Related Subsidiaries

Editorial Notes

Amendments

1978—Subsec. (d). Pub. L. 95–599 substituted “$65,000,000” for “$50,000,000”. 1976—Subsec. (d). Pub. L. 94–280 substituted “$50,000,000” for “$27,761,000”. 1975—Subsec. (d). Pub. L. 93–643 substituted “$27,761,000” for “$25,261,000”. 1973—Subsec. (d). Pub. L. 93–87 substituted “$25,261,000” for “$16,761,000”. 1970—Subsec. (d). Pub. L. 91–605 substituted “$16,761,000” for “$13,000,000”. 1964—Subsec. (b). Pub. L. 88–423 substituted “which such bridge is to be located, or the appropriate subdivision of such State, shall enter into an agreement with such agency and with” for “such State, shall enter into an agreement with such agency and with which such bridge is to be located, or the appropriate subdivision of”. 1959—Subsec. (d). Pub. L. 86–342 substituted “$13,000,000” for “$10,000,000”.

Statutory Notes and Related Subsidiaries

Appropriation Out of Highway Trust Fund of Sums Appropriated Under Authority of Increased Authorization Pub. L. 95–599, title I, § 128(b), Nov. 6, 1978, 92 Stat. 2707, provided that: “Sums appropriated or expended under authority of the increased authorization established by the amendment made by subsection (a) of this section [amending subsec. (d) of this section] shall be appropriated out of the Highway Trust Fund for the fiscal year ending
September 30, 1978, and for subsequent fiscal years.” Appropriation of Increased Authorization Pub. L. 94–280, title I, § 137(b),
May 5, 1976, 90 Stat. 443, provided that: “Sums appropriated or expended under authority of the increased authorization established by the amendment made by subsection (a) of this section [to subsec. (d) of this section] shall be appropriated out of the Highway Trust Fund for the fiscal year ending
September 30, 1977, and for subsequent fiscal years.” Restriction on Increased Authorization of Appropriations Pub. L. 93–643, § 123(b), Jan. 4, 1975, 88 Stat. 2290, provided that: “All sums appropriated under authority of the increased authorization established by the amendment made by subsection (a) of this section shall be available for expenditure in the same manner and for the same purpose as provided for in subsection (b) of section 116 of the Federal-Aid Highway Act of 1970 (Public Law 91–605).” Pub. L. 93–87, title I, § 128(b), Aug. 13, 1973, 87 Stat. 265, provided that: “All sums appropriated under authority of the increased authorization of $8,500,000 established by the amendment made by subsection (a) of this section [to subsec. (d) of this section] shall be available for expenditure only in connection with the

Construction

of a bridge across lock and dam numbered 13 on the Arkansas River near Fort Smith, Arkansas, in the amount of $2,100,000 and in connection with re

Construction

of a bridge across the Chickamauga Dam on the Tennessee River near Chattanooga, Tennessee, in the amount of $6,400,000. No such sums shall be appropriated until all applicable requirements of section 320 of title 23 of the United States Code have been complied with by the appropriate Federal agency, the Secretary of Transportation, and the State of Arkansas for the Fort Smith project, and the State of Tennessee for the Chattanooga project.” Pub. L. 91–605, title I, § 116(b), Dec. 31, 1970, 84 Stat. 1724, provided that: “All sums appropriated under authority of the increased authorization of $3,761,000 established by the amendment made by subsection (a) of this section [amending subsec. (d) of this section] shall be available for expenditure only in connection with the

Construction

of a bridge across Markland Dam on the Ohio River near Markland, Indiana, and Warsaw, Kentucky. No such sums shall be appropriated until all applicable requirements of section 320 of title 23 of the United States Code have been complied with by the appropriate Federal agency, the Secretary of Transportation, and the States of Kentucky and Indiana.”

Reference

Citations & Metadata

Citation

23 U.S.C. § 320

Title 23Highways

Last Updated

Apr 6, 2026

Release point: 119-73