Adds a new paragraph (T) to 23 U.S.C. 119(d)(2) making construction of projects eligible for assistance under the REPAIR infrastructure program (section 11509 of the IIJA) eligible under the National Highway Performance Program provision.

Inserts a new paragraph (4) into subsection (b) to list projects eligible under the REPAIR infrastructure program as eligible under the Surface Transportation Block Grant Program; and renumbers a cross-reference in subsection (c)(2) (striking "(5)" and inserting "(4)").

Makes multiple amendments to the Highway Safety Improvement Program provisions: redesignates existing paragraphs (1)–(16) as (2)–(17); inserts a new paragraph (1) defining the term "divisive roadway infrastructure" (including limited access highways, viaducts, and principal arterial facilities); inserts a clause adding projects eligible under the REPAIR infrastructure program to the list of eligible projects; and updates clause numbering and cross-references in subsections (c) and (d) accordingly.

Adds a new paragraph (12) to subsection (b) to make projects eligible for assistance under the REPAIR infrastructure program eligible under the Congestion Mitigation and Air Quality Improvement (CMAQ) Program.

Adds a new clause (viii) to section 165(c)(6)(A) to include projects eligible under the REPAIR infrastructure program as eligible under the Territorial Highway Program.

Redesignates clauses (xxii) and (xxiii) as (xxiii) and (xxiv), respectively, and inserts a new clause (xxii) making projects eligible under the REPAIR infrastructure program eligible under the National Highway Freight Program clause list; updates following clause numbering accordingly.

Adds a new subparagraph (H) to 173(e)(1) to include projects eligible for assistance under the REPAIR infrastructure program as eligible under the Rural Surface Transportation Grant Program.

Strikes existing paragraph (2) of section 175(c) and inserts a new paragraph (2) entitled "Flexibility," which (A) requires a State, if the Secretary makes a certification described in subparagraph (B), to first use funds apportioned under section 104(b)(7) for projects eligible under the REPAIR infrastructure program (taking into account planning grants under that program) and, if funds remain, to use funds for other eligible projects; and (B) defines the certification as a Secretary determination that the State has demonstrated reductions in transportation emissions on a per capita basis and per unit of economic output.