Code of Federal Regulations > Title 23 > Chapter I - CHAPTER I—FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION

U.S. Code of Federal Regulations

Regulations most recently checked for updates: Jan 21, 2026

Part 1 [§ 1.1 - § 1.36] - PART 1—GENERAL

Part 140 [§ 140.501 - § 140.922] - PART 140—REIMBURSEMENT

Part 172 [§ 172.1 - § 172.11] - PART 172—PROCUREMENT, MANAGEMENT, AND ADMINISTRATION OF ENGINEERING AND DESIGN RELATED SERVICES

Part 180 [§ 180.1 - § 180.1] - PART 180—CREDIT ASSISTANCE FOR SURFACE TRANSPORTATION PROJECTS

Part 190 [§ 190.1 - § 190.7] - PART 190—INCENTIVE PAYMENTS FOR CONTROLLING OUTDOOR ADVERTISING ON THE INTERSTATE SYSTEM

Part 192 [§ 192.1 - § 192.7] - PART 192—DRUG OFFENDER'S DRIVER'S LICENSE SUSPENSION

Part 200 [§ 200.1 - § 200.11] - PART 200—TITLE VI PROGRAM AND RELATED STATUTES—IMPLEMENTATION AND REVIEW PROCEDURES

Part 230 [§ 230.101 - § 230.415] - PART 230—EXTERNAL PROGRAMS

Part 260 [§ 260.101 - § 260.407] - PART 260—EDUCATION AND TRAINING PROGRAMS

Part 420 [§ 420.101 - § 420.209] - PART 420—PLANNING AND RESEARCH PROGRAM ADMINISTRATION

Part 450 [§ 450.100 - § 450.340] - PART 450—PLANNING ASSISTANCE AND STANDARDS

Part 460 [§ 460.1 - § 460.3] - PART 460—PUBLIC ROAD MILEAGE FOR APPORTIONMENT OF HIGHWAY SAFETY FUNDS

Part 470 [§ 470.101 - § 470.115] - PART 470—HIGHWAY SYSTEMS

Part 490 [§ 490.101 - § 490.811] - PART 490—NATIONAL PERFORMANCE MANAGEMENT MEASURES

Part 500 - PART 500 [RESERVED]

Part 505 - PART 505 [RESERVED]

Part 511 [§ 511.301 - § 511.315] - PART 511—REAL-TIME SYSTEM MANAGEMENT INFORMATION PROGRAM

Part 515 [§ 515.1 - § 515.19] - PART 515—ASSET MANAGEMENT PLANS

Part 620 [§ 620.101 - § 620.203] - PART 620—ENGINEERING

Part 624 [§ 624.1 - § 624.13] - PART 624—INTERSTATE SYSTEM ACCESS

Part 625 [§ 625.1 - § 625.4] - PART 625—DESIGN STANDARDS FOR HIGHWAYS

Part 626 [§ 626.1 - § 626.3] - PART 626—PAVEMENT POLICY

Part 627 [§ 627.1 - § 627.9] - PART 627—VALUE ENGINEERING

Part 630 [§ 630.102 - § 630.1112] - PART 630—PRECONSTRUCTION PROCEDURES

Part 633 [§ 633.101 - § 633.104] - PART 633—REQUIRED CONTRACT PROVISIONS

Part 635 [§ 635.101 - § 635.606] - PART 635—CONSTRUCTION AND MAINTENANCE

Part 636 [§ 636.101 - § 636.514] - PART 636—DESIGN-BUILD CONTRACTING

Part 637 [§ 637.201 - § 637.209] - PART 637—CONSTRUCTION INSPECTION AND APPROVAL

Part 645 [§ 645.101 - § 645.309] - PART 645—UTILITIES

Part 646 [§ 646.101 - § 646.220] - PART 646—RAILROADS

Part 650 [§ 650.101 - § 650.809] - PART 650—BRIDGES, STRUCTURES, AND HYDRAULICS

Part 652 - PART 652 [RESERVED]

Part 655 [§ 655.601 - § 655.607] - PART 655—TRAFFIC OPERATIONS

Part 656 [§ 656.1 - § 656.7] - PART 656—CARPOOL AND VANPOOL PROJECTS

Part 657 [§ 657.1 - § 657.21] - PART 657—CERTIFICATION OF SIZE AND WEIGHT ENFORCEMENT

Part 658 [§ 658.1 - § 658.23] - PART 658—TRUCK SIZE AND WEIGHT, ROUTE DESIGNATIONS—LENGTH, WIDTH AND WEIGHT LIMITATIONS

Part 660 [§ 660.501 - § 660.519] - PART 660—SPECIAL PROGRAMS (DIRECT FEDERAL)

Part 661 [§ 661.1 - § 661.57] - PART 661—TRIBAL TRANSPORTATION FACILITY BRIDGE PROGRAM (TTFBP)

Part 667 [§ 667.1 - § 667.9] - PART 667—PERIODIC EVALUATION OF FACILITIES REPEATEDLY REQUIRING REPAIR AND RECONSTRUCTION DUE TO EMERGENCY EVENTS

Part 668 [§ 668.101 - § 668.215] - PART 668—EMERGENCY RELIEF PROGRAM

Part 669 [§ 669.1 - § 669.21] - PART 669—ENFORCEMENT OF HEAVY VEHICLE USE TAX

Part 680 [§ 680.100 - § 680.118] - PART 680—NATIONAL ELECTRIC VEHICLE INFRASTRUCTURE STANDARDS AND REQUIREMENTS

Part 710 [§ 710.101 - § 710.709] - PART 710—RIGHT-OF-WAY AND REAL ESTATE

Part 750 [§ 750.101 - § 750.713] - PART 750—HIGHWAY BEAUTIFICATION

Part 751 [§ 751.1 - § 751.25] - PART 751—JUNKYARD CONTROL AND ACQUISITION

Part 752 [§ 752.1 - § 752.11] - PART 752—LANDSCAPE AND ROADSIDE DEVELOPMENT

Part 771 [§ 771.101 - § 771.141] - PART 771—ENVIRONMENTAL IMPACT AND RELATED PROCEDURES

Part 772 [§ 772.1 - § 772.19] - PART 772—PROCEDURES FOR ABATEMENT OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE

Part 773 [§ 773.101 - § 773.117] - PART 773—SURFACE TRANSPORTATION PROJECT DELIVERY PROGRAM APPLICATION REQUIREMENTS AND TERMINATION

Part 774 [§ 774.1 - § 774.17] - PART 774—PARKS, RECREATION AREAS, WILDLIFE AND WATERFOWL REFUGES, AND HISTORIC SITES (SECTION 4(f))

Part 777 [§ 777.1 - § 777.11] - PART 777—MITIGATION OF IMPACTS TO WETLANDS AND NATURAL HABITAT

Part 778 [§ 778.101 - § 778.113] - PART 778—PILOT PROGRAM FOR ELIMINATING DUPLICATION OF ENVIRONMENTAL REVIEWS

Part 810 [§ 810.2 - § 810.310] - PART 810—MASS TRANSIT AND SPECIAL USE HIGHWAY PROJECTS

Part 924 [§ 924.1 - § 924.17] - PART 924—HIGHWAY SAFETY IMPROVEMENT PROGRAM

Part 940 [§ 940.1 - § 940.13] - PART 940—INTELLIGENT TRANSPORTATION SYSTEM ARCHITECTURE AND STANDARDS

Part 950 [§ 950.1 - § 950.9] - PART 950—ELECTRONIC TOLL COLLECTION

Part 970-999 - PARTS 970-999 [RESERVED]