Multiplex Index
- Gallery of shields along roads with more than one route number.
- http://www.m-plex.com/roads/mpindex.html

AARoads Roadtrips
- Contains photographic logs of various routes in the East-Central region.
- http://www.aaroadtrips.com/

Redhighways.com
- Text guides to various U.S. Highways, with links.
- http://www.redhighways.com/

Green Highways Partnership
- Multi-sector initiative that seeks to incorporate environmental sustainability into all surface transportation infrastructure. Site includes FAQ, media resources, and contact information.
- http://www.greenhighways.org/

Road Geek Stuff
- Includes various topics.
- http://www.mylandofmisery.com/roads.htm

Summer of 6
- Weblog of a 2006 trip documenting U.S. 6 in comments and photographs.
- http://www.floodgap.com/roadgap/6/

The Interstate is 50
- American Association of State Highway and Transportation Officials page commemorating the 50th anniversary of the Interstate System in 2006. Includes history and photographs.
- http://www.interstate50th.org/

Roadsidephotos.sabr.org
- Contains information about certain highways culled from cross-country trips. Includes maps.
- http://roadsidephotos.sabr.org/

Ports-to-Plains Trade Corridor
- Coalition to improve north-south transport in the West-Central part of the country. Site includes maps, construction information, and contact information.
- http://www.portstoplains.com/

Expressways Online
- Commentary and articles about relevant issues, authored by a former editor of Roads and Bridges magazine.
- http://www.expresswaysonline.com/

U.S. Code of Federal Regulations Title 23 - Highways
- Complete contents of the 2005 revision.
- http://www.access.gpo.gov/cgi-bin/cfrassemble.cgi?title=200523

Adopt A Highway Maintenance Corporation
- Provides for sponsorship in various states.
- http://www.adoptahighway.com/

American Byways
- Covers Kentucky, Ohio Tennessee, Virginia, and West Virginia and surrounding areas. Site includes photography, historical information, and forum.
- http://www.americanbyways.com/

Places 2 Drive
- Guide to scenic drives, roadside attractions, automotive events and car accessories, with public submissions.
- http://www.places2drive.com/

United States Code Title 23 - Highways
- Complete contents of the document.
- http://www.access.gpo.gov/uscode/title23/title23.html

U.S. Route 6 Tourist Association
- Covers the entirety of the route. Page includes background, news articles, and maps.
- http://www.route6tour.com/

American Highway Users Alliance
- Interest group representing motor vehicle users and businesses promoting highway safety and efficiency. Site includes news updates and Rules of the Road publication information.
- http://www.highways.org/

The ZZYZX Interstate Highway List
- Gives an overview of the system and provides a listing of all one- and two-digit routes.
- http://www.ihoz.com/interstates.html

Larry's Phat Page - Highways
- Route logs of and personal travel comments about various highways, primarily Interstates.
- http://www.phatpage.org/highways.html

Gorp's Top Ten US Scenic Drives
- List which includes details on the Blue Ridge Parkway, Seward Highway, California 1, Vermont 100, and the Custer Scenic Byway.
- http://gorp.away.com/gorp/activity/byway/topten.htm

Heartland Expressway
- A proposed divided highway running between Rapid City, South Dakota and Denver, Colorado, also known as High Priority Corridor 14 of the Intermodal Surface Transportation Efficiency Act of 1991. Site includes maps, project status, and various other facts
- http://www.heartlandexpressway.com/

Road Stuff
- Much Northeast coverage. Also includes photos, map scans, and a log of Route 9's in the country.
- http://neilbert.com/roads/

American Society of Highway Engineers
- Newsletters, FAQ, and other features relevant to the trade.
- http://www.highwayengineers.org/

MotorcycleRoads.US
- Compilation of lists specifically for motorcyclists who prefer scenic or winding routes.
- http://www.motorcycleroads.us/

Interstate-Guide.com
- Includes the Interstate Guide, the List of Interstate Business Routes, and the Interstate Shield Gallery. Extensive coverage.
- http://www.interstate-guide.com/

Corporate Sponsor Adopt A Highway Program
- Lists the steps which may be taken for Adopt-A-Highway Litter Removal Service of America, Incorporated to manage the section which is requested. Includes option to receive visual impressions.
- http://www.adoptahighway.net/

National Cooperative Highway Research Program - Projects
- Listings for this division of the Transportation Research Board, a unit of the National Research Council.
- http://www4.trb.org/trb/crp.nsf/NCHRP+projects

Midwestroads.com
- Covers the respective region of the country. Includes historic maps, planning documents and reports, and photos.
- http://www.midwestroads.com/

Coast to Coast on US 50
- History and other information.
- http://www.route50.com/

The Road Information Program
- Nonprofit organization promoting policies which are designed to improve traffic conditions.
- http://www.tripnet.org/

Highway Deficiencies
- A compendium of substandard features.
- http://www.ajfroggie.com/roads/deficiency/

American Association of State Highway and Transportation Officials
- Much information on this consortium.
- http://www.transportation.org/

SmarTraveler
- Traffic reports for cities and other travel information.
- http://www.smartraveler.com/

U.S. Hwy. 90 - The Southern Route 66
- Travelogue and old postcard scans. Page linked is Louisiana but there are also pages on Texas, Mississippi, Alabama, and Florida.
- http://ucmmuseum.com/hwy90la.htm

Road Trip USA
- Great detail on various at-grade long-distance routes.
- http://www.roadtripusa.com/

US Road Conditions.com
- Gives links to each state's respective webpages.
- http://www.usroadconditions.com/

3-digit Interstate Highways
- Location, history, and trivia. Includes ones that were proposed but never built.
- http://www.kurumi.com/roads/3di/

Bygone Byways
- Descriptions of current and former US routes 66, 80, 99, and 101 as well as other notes.
- http://www.bygonebyways.com/

US Highways: From US 1 to US 830
- Complete list including historic, plus other features.
- http://www.us-highways.com/

High Priority Corridors
- Information about these highways which have been set aside as most important in the 1998 bill "Transportation Equity Act for the 21st Century (TEA-21)".
- http://www.aaroads.com/high-priority/

Appalachian Regional Commission Development Corridors
- Unofficial site which explains these potential thoroughfares.
- http://www.aaroads.com/arc/

Route 40 - National Road
- Guide to the first federally-funded road in the U.S. (1800s) and the route which followed it later (US 40).
- http://www.route40.net/

Highway History
- Federal Highway Administration page with a collection of articles including those on U.S. Highway numbering and creation of the Interstate system.
- http://www.fhwa.dot.gov/infrastructure/history.htm

1999 Road to Ruin Report
- Written by Friends of the Earth and Taxpayers for Common Sense, this lists what they think are the 50 most wasteful road projects in America.
- http://www.taxpayer.net/TCS/RoadRuin/roads.htm

US Route 20
- Information and some history.
- http://www.usroute20.com/

US Highway 101: Guide to the Pacific Coast Highway
- Covers many aspects.
- http://www.us-101.com/

Southern Highroads Trail
- A designated scenic highway going through Georgia, Tennessee, North Carolina and South Carolina. Official tourism site.
- http://southernhighroads.org/

Highways.TV
- Links to state transportation resources throughout the country including weather, cams, reports, and hotel reservations.
- http://www.highways.tv/