Title 23 — Highways
- Chapter I Federal Highway Administration, Department of Transportation
- Subchapter A General Management and Administration
- Subchapter B Payment Procedures
- Part 140 – Reimbursement
- Part 172 – Procurement, Management, and Administration of Engineering and Design Related Services
- Part 180 – Credit Assistance for Surface Transportation Projects
- Part 190 – Incentive Payments for Controlling Outdoor Advertising on the Interstate System
- Part 192 – Drug Offender's Driver's License Suspension
- Subchapter C Civil Rights
- Subchapter D National Highway Institute
- Subchapter E Planning and Research
- Subchapter F Transportation Infrastructure Management
- Subchapter G Engineering and Traffic Operations
- Part 620 – Engineering
- Part 624 – Interstate System Access
- Part 625 – Design Standards for Highways
- Part 626 – Pavement Policy
- Part 627 – Value Engineering
- Part 630 – Preconstruction Procedures
- Part 635 – Construction and Maintenance
- Part 636 – Design-Build Contracting
- Part 637 – Construction Inspection and Approval
- Part 645 – Utilities
- Part 646 – Railroads
- Part 650 – Bridges, Structures, and Hydraulics
- Part 655 – Traffic Operations
- Part 656 – Carpool and Vanpool Projects
- Part 657 – Certification of Size and Weight Enforcement
- Part 658 – Truck Size and Weight, Route Designations—Length, Width and Weight Limitations
- Part 660 – Special Programs (Direct Federal)
- Part 661 – Tribal Transportation Facility Bridge Program (TTFBP)
- Part 667 – Periodic Evaluation of Facilities Repeatedly Requiring Repair and Reconstruction Due to Emergency Events
- Part 668 – Emergency Relief Program
- Part 669 – Enforcement of Heavy Vehicle Use Tax
- Part 680 – National Electric Vehicle Infrastructure Standards and Requirements
- Subchapter H Right-of-Way and Environment
- Part 710 – Right-of-Way and Real Estate
- Part 750 – Highway Beautification
- Part 751 – Junkyard Control and Acquisition
- Part 752 – Landscape and Roadside Development
- Part 771 – Environmental Impact and Related Procedures
- Part 772 – Procedures for Abatement of Highway Traffic Noise and Construction Noise
- Part 773 – Surface Transportation Project Delivery Program Application Requirements and Termination
- Part 774 – Parks, Recreation Areas, Wildlife and Waterfowl Refuges, and Historic Sites (Section 4(f))
- Part 777 – Mitigation of Impacts to Wetlands and Natural Habitat
- Part 778 – Pilot Program for Eliminating Duplication of Environmental Reviews
- Subchapter I Public Transportation
- Subchapter J Highway Safety
- Subchapter K Intelligent Transportation Systems
- Subchapter L Federal Lands Highways
- Chapter II National Highway Traffic Safety Administration and Federal Highway Administration, Department of Transportation
- Subchapter A Procedures for State Highway Safety Programs
- Subchapter B Guidelines
- Part 1208 – National Minimum Drinking Age
- Part 1210 – Operation of Motor Vehicles by Intoxicated Minors
- Part 1215 – Use of Safety Belts—Compliance and Transfer-of-Funds Procedures
- Part 1225 – Operation of Motor Vehicles by Intoxicated Persons
- Part 1235 – Uniform System for Parking for Persons with Disabilities
- Part 1240 – Safety Incentive Grants for Use of Seat Belts—Allocations Based on Seat Belt Use Rates
- Subchapter C General Provisions
- Subchapter D Transfer and Sanction Programs
- Chapter III National Highway Traffic Safety Administration, Department of Transportation