Title 23—Highways--Volume 1
PART 625—DESIGN STANDARDS FOR HIGHWAYS
§ 625.1   Purpose.
To designate those standards, policies, and standard specifications that are acceptable to the Federal Highway Administration (FHWA) for application in the geometric and structural design of highways.
§ 625.2   Policy.
(a) Plans and specifications for proposed National Highway System (NHS) projects shall provide for a facility that will—
(1) Adequately serve the existing and planned future traffic of the highway in a manner that is conducive to safety, durability, and economy of maintenance; and
(2) Be designed and constructed in accordance with criteria best suited to accomplish the objectives described in paragraph (a)(1) of this section and to conform to the particular needs of each locality.
(b) Resurfacing, restoration, and rehabilitation (RRR) projects shall be constructed in accordance with standards that preserve and extend the service life of highways and enhance highway safety. Resurfacing, restoration, and rehabilitation work includes placement of additional surface material and/or other work necessary to return an existing roadway, including shoulders, bridges, the roadside, and appurtenances to a condition of structural or functional adequacy.
(c) An important goal of the FHWA is to provide the highest practical and feasible level of safety for people and property associated with the Nation's highway transportation systems and to reduce highway hazards and the resulting number and severity of accidents on all the Nation's highways.
§ 625.3   Application.
(a) Applicable standards. (1) Design and construction standards for new construction, reconstruction, resurfacing (except for maintenance resurfacing), restoration, or rehabilitation of a highway on the NHS shall be those approved by the Secretary in cooperation with the State DOTs. These standards must consider, in addition to the criteria described in § 625.2(a), the following:
(i) The constructed and natural environment of the area;
(ii) The environmental, scenic, aesthetic, historic, community, and preservation impacts of the activity;
(iii) Cost savings by utilizing flexibility that exists in current design guidance and regulations; and
(iv) Access for other modes of transportation.
(2) Federal-aid projects not on the NHS are to be designed, constructed, operated, and maintained in accordance with State laws, regulations, directives, safety standards, design standards, and construction standards.
(3) Interstate highways located in Alaska and Puerto Rico shall be designed in accordance with such geometric and construction standards as are adequate for current and probable future traffic demands and the needs of the locality of the highway.
(4) A State may allow a local jurisdiction to design a project using a roadway design publication that is different from the roadway design publication used by the State in which the local jurisdiction resides if—
(i) The local jurisdiction is a direct recipient of Federal funds for the project;
(ii) The roadway design publication is adopted by the local jurisdiction and recognized by FHWA;
(iii) The design complies with all applicable Federal laws and regulations; and
(iv) The project is located on a roadway that is owned by the local jurisdiction and is not part of the Interstate System.
(b) Deviations from specific minimum values on the NHS. The standards, policies, and standard specifications cited in § 625.4 of this part contain specific criteria and controls for the design of NHS projects. Deviations from specific minimum values therein are to be handled in accordance with procedures in paragraph (f) of this section. If there is a conflict between criteria in the documents enumerated in § 625.4 of this part, the latest listed standard, policy, or standard specification will govern.
(c) Application of other FHWA regulations. Application of FHWA regulations, although cited in § 625.4 of this part as standards, policies, and standard specifications, shall be as set forth therein.
(d) Funding source. This regulation establishes Federal standards for work on the NHS regardless of funding source.
(e) Very minor or no roadway work. The Division Administrator shall determine the applicability of the roadway geometric design standards to traffic engineering, safety, and preventive maintenance projects which include very minor or no roadway work. Formal findings of applicability are expected only as needed to resolve controversies.
(f) Exceptions —(1) Project exception. (i) Approval within the delegated authority provided by FHWA Order M1100.1A may be given on a project basis to designs on the NHS which do not conform to the minimum criteria as set forth in the standards, policies, and standard specifications for:
(A) Experimental features on projects; and
(B) Projects where conditions warrant that exceptions be made.
(ii) The determination to approve a project design that does not conform to the minimum criteria is to be made only after due consideration is given to all project conditions such as maximum service and safety benefits for the dollar invested, compatibility with adjacent sections of roadway and the probable time before reconstruction of the section due to increased traffic demands or changed conditions.
(2) Programmatic exception. Approval within the delegated authority provided by FHWA Order M1100.1A may be given, on a programmatic basis, to use a more recent edition of any standard or specification incorporated by reference under § 625.4(d).
§ 625.4   Standards, policies, and standard specifications.
(a) Roadway and appurtenances. (1) A Policy on Geometric Design of Highways and Streets, AASHTO (incorporated by reference; see paragraph (d) of this section).
(2) A Policy on Design Standards—Interstate System, AASHTO (paragraph (d) of this section).
(3) The geometric design standards for resurfacing, restoration, and rehabilitation (RRR) projects on NHS highways shall be the procedures or the design criteria established for individual projects, groups of projects, or all RRR projects in a State, and as approved by FHWA. The RRR design standards shall reflect the consideration of the traffic, safety, economic, physical, community, and environmental needs of the projects. If a State does not adopt design procedures or criteria for RRR projects as approved by FHWA, the standards listed in paragraphs (a)(1) and (2) shall apply.
(4) Location and Hydraulic Design of Encroachments on Flood Plains, refer to 23 CFR part 650, subpart A.
(5) Procedures for Abatement of Highway Traffic Noise and Construction Noise, refer to 23 CFR part 772.
(6) Accommodation of Utilities, refer to 23 CFR part 645, subpart B.
(7) Pavement Design, refer to 23 CFR part 626.
(b) Bridges and structures. (1) For existing bridges originally designed to any edition of the AASHTO Standard Specifications for Highway Bridges, modifications may be designed to the Standard Specifications for Highway Bridges, 17th Edition, AASHTO, 2002 (incorporated by reference; see § 625.4(d)), or to the standards and specifications that are listed in § 625.4(b).
(2) AASHTO LRFD Bridge Construction Specifications (paragraph (d) of this section).
(3) AASHTO LRFD Bridge Design Specifications (paragraph (d) of this section).
(4) AASHTO LRFD Movable Highway Bridge Design Specifications (paragraph (d) of this section).
(5) AASHTO/AWS D1.5M/D1.5 Bridge Welding Code (paragraph (d) of this section).
(6) AWS D1.4/D1.4M Structural Welding Code—Reinforcing Steel (paragraph (d) of this section).
(7) AASHTO Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals, (paragraph (d) of this section); or AASHTO LRFD Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals (paragraph (d) of this section).
(8) Navigational Clearances for Bridges, refer to 23 CFR part 650, subpart H.
(9) AWS D1.1/D1.1M Structural Welding Code—Steel (paragraph (d) of this section).
(c) Materials. (1) General Materials Requirements, refer to 23 CFR part 635, subpart D.
(2) Quality Assurance Procedures for Construction, refer to 23 CFR part 637, subpart B.
(d) Documents incorporated by reference. The standards required in this section are incorporated by reference into this section with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. All approved material is available for inspection at U.S. Department of Transportation's National Transportation Library at 1200 New Jersey Avenue SE, Washington, DC 20590; (800) 853-1351 and is available from the sources indicated below. It is also available for inspection at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, email fr.inspection@nara.gov or go to www.archives.gov/federal-register/cfr/ibr-locations.html.
(1) American Association of State Highway and Transportation Officials (AASHTO), 555 12th Street NW, Suite 1000, Washington, DC 20004, 1-800-231-3475, https://store.transportation.org.
(i) AASHTO GDHS-7, A Policy on Geometric Design of Highways and Streets, 7th Edition, 2018.
(ii) A Policy on Design Standards—Interstate System, May 2016.
(iii) Standard Specifications for Highway Bridges, 17th Edition, 2002
(iv) AASHTO-LRFD Bridge Construction Specifications, 4th Edition, copyright 2017.
(v) AASHTO LRFD-8, LRFD Bridge Design Specifications, 8th Edition, 2017.
(vi) AASHTO LRFD Movable Highway Bridge Design Specifications, 2nd Edition, 2007, with:
(A) Interim Revisions, 2008,
(B) Interim Revisions, 2010,
(C) Interim Revisions, 2011,
(D) Interim Revisions, 2012,
(E) Interim Revisions, 2014,
(F) Interim Revisions, 2015, and
(G) Interim Revisions, 2018.
(vii) [Reserved]
(viii) AASHTO LTS-6, Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals, 6th Edition, copyright 2013, with:
(A) AASHTO LTS-6-I1, 2015 Interim Revisions to Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals, copyright 2014,
(B) AASHTO LTS-6-I2-OL, 2019 Interim Revisions to Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals, copyright 2018, and
(C) AASHTO LTS-6-I3, 2020 Interim Revisions to Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals, copyright 2019.
(ix) AASHTO LRFDLTS-1, LRFD Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals, 1st Edition, copyright 2015, with:
(A) AASHTO LRFDLTS-1-I1-OL, 2017 Interim Revisions to LRFD Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals, copyright 2016,
(B) AASHTO LRFDLTS-1-I2-OL, 2018 Interim Revisions to LRFD Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals, copyright 2017,
(C) AASHTO LRFDLTS-1-I3-OL, 2019 Interim Revisions to LRFD Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals, copyright 2018, and
(D) AASHTO LRFDLTS-1-I4, 2020 Interim Revisions to LRFD Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals, copyright 2019.
(2) American Welding Society (AWS), 8669 NW 36 Street, #130 Miami, FL 33166-6672; www.aws.org; or (800) 443-9353 or (305) 443-9353.
(i) AWS D1.1/D1.1M:2015 Structural Welding Code—Steel, 23rd Edition, copyright 2015, including Errata March 2016 (second printing).
(ii) AWS D1.4/D1.4M:2011 Structural Welding Code -Reinforcing Steel, 2011.
(iii) AASHTO/AWS D1.5M/D1.5: 2015-AMD1, Bridge Welding Code, 7th Edition, Amendment: December 12, 2016.
(e) Additional design resources. The FHWA supports using, as design resources to achieve context sensitive designs, guides that national organizations develop from peer-reviewed research, or equivalent guides that are developed in cooperation with State or local officials, when such guides are not in conflict with Federal laws and regulations.