Title 23 › CHAPTER 1 — FEDERAL-AID HIGHWAYS › § 175
Creates a federal carbon reduction program to cut carbon dioxide from on-road vehicles in each State. It lets States use funds given under section 104(b)(7) for projects that lower transportation emissions. Eligible work includes many types of projects, such as traffic monitoring and control, public transit, walking and biking paths, smart traffic and vehicle-to-infrastructure tech, electric vehicle and other alternative fuel stations, energy-efficient street lighting, diesel engine retrofits, freight and port improvements, replacing vehicles and equipment with zero-emission models, congestion pricing and other demand-management strategies, and the State’s carbon reduction plan itself. A State can also use the funds for other projects under section 133(b) if the Secretary certifies the State has cut emissions per person and per unit of economic output. Key terms: metropolitan planning organization (local regional planning body); urbanized area (a densely populated area); transportation emissions (CO2 from on-road sources in a State); transportation management area (a big metro area designated by the Secretary). Each State must make a carbon reduction strategy within 2 years after the Surface Transportation Reauthorization Act of 2021 took effect, update it at least every 4 years, and get it reviewed within 90 days. For each year, 65 percent of the funds must be spent by population across four size groups (>200,000; 50,000–200,000; 5,000–49,999; <5,000), with rules for coordination with local planning groups. Federal cost share rules follow section 120, and projects are treated as Federal-aid highway projects.
Full Legal Text
Highways, Source: USLM XML via OLRC
Legislative History
Reference
Citation
23 U.S.C. § 175
Title 23, Highways
Last Updated
Sep 22, 2026
Release point: 119-110