| 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. |
| 3-digit Interstate Highways: Location, history, and trivia. Includes ones that were proposed but never built. |
| 3dis that Aren't--State Route Spurs and Loops: Information about state routes that could be an interstate of the same number. |
| Adopt A Highway Maintenance Corporation: Provides for sponsorship in various states. |
| American Association of State Highway and Transportation Officials: Much information on this consortium. |
| American Byways: Covers Kentucky, Ohio Tennessee, Virginia, and West Virginia and surrounding areas. Site includes photography, historical information, and forum. |
| 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. |
| American Society of Highway Engineers: Newsletters, FAQ, and other features relevant to the trade. |
| Appalachian Regional Commission Development Corridors: Unofficial site which explains these potential thoroughfares. |
| Bygone Byways: Descriptions of current and former US routes 66, 80, 99, and 101 as well as other notes. |
| Coast to Coast on US 50: History and other information. |
| 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. |
| Expressways Online: Commentary and articles about relevant issues, authored by a former editor of Roads and Bridges magazine. |
| 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. |
| 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. |
| 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)". |
| Highway Deficiencies: A compendium of substandard features. |
| Highway History: Federal Highway Administration page with a collection of articles including those on U.S. Highway numbering and creation of the Interstate system. |
| Highways and Gas Stations: Includes information on various highways in Minnesota, Missouri, Ohio, and Pennsylvania. |
| Highways.TV: Links to state transportation resources throughout the country including weather, cams, reports, and hotel reservations. |
| Interstate-Guide.com: Includes the Interstate Guide, the List of Interstate Business Routes, and the Interstate Shield Gallery. Extensive coverage. |
| Kim Russell's U.S. Highways Page: Gives brief descriptions of all U.S.-numbered routes, past and present, as well as suggestions for possible future routings. |
| Larry's Phat Page - Highways: Route logs of and personal travel comments about various highways, primarily Interstates. |
| Michelle Skinner's Interstate Page: Gives descriptions of each route. |
| Midwestroads.com: Covers the respective region of the country. Includes historic maps, planning documents and reports, and photos. |
| MotorcycleRoads.US: Compilation of lists specifically for motorcyclists who prefer scenic or winding routes. |
| National Cooperative Highway Research Program - Projects: Listings for this division of the Transportation Research Board, a unit of the National Research Council. |
| New England Turnpikes: Information, exit lists, and photos of the modern-day turnpikes. |
| Pete's Road Site: Covers various topics in various regions east of the Mississippi, with a Cincinnati/Atlanta focus. |
| Places 2 Drive: Guide to scenic drives, roadside attractions, automotive events and car accessories, with public submissions. |
| 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. |
| Road Geek Stuff: Includes various topics. |
| Road Stuff: Much Northeast coverage. Also includes photos, map scans, and a log of Route 9's in the country. |
| Road Trip USA: Great detail on various at-grade long-distance routes. |
| Roads, Highways and Trails: Detailed personal travelogue. |
| Roadsidephotos.sabr.org: Contains information about certain highways culled from cross-country trips. Includes maps. |
| 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). |
| SmarTraveler: Traffic reports for cities and other travel information. |
| Southern Highroads Trail: A designated scenic highway going through Georgia, Tennessee, North Carolina and South Carolina. Official tourism site. |
| Southern Highways: Various scenes from along the southern tier of the country. |
| Summer of 6: Weblog of a 2006 trip documenting U.S. 6 in comments and photographs. |
| The Interstate Archive: Gives information with city maps and longitude and latitude information. |
| 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. |
| The Road Information Program: Nonprofit organization promoting policies which are designed to improve traffic conditions. |
| The ZZYZX Interstate Highway List: Gives an overview of the system and provides a listing of all one- and two-digit routes. |
| Tim's Highway Page: Gives text descriptions and locator maps for various routes, primarily in Washington State. |
| Traffic Counts: List of Average Daily Traffic (ADT) tallies for major metropolitan areas. |
| U.S. Code of Federal Regulations Title 23 - Highways: Complete contents of the 2005 revision. |
| 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. |
| U.S. Route 6 Tourist Association: Covers the entirety of the route. Page includes background, news articles, and maps. |
| United States Code Title 23 - Highways: Complete contents of the document. |
| US Highway 101: Guide to the Pacific Coast Highway: Covers many aspects. |
| US Highways: From US 1 to US 830: Complete list including historic, plus other features. |
| US Road Conditions.com: Gives links to each state's respective webpages. |
| US Route 20: Information and some history. |
| USroadman.com: Log of travels along U.S.-numbered routes. Includes route histories and links to photographs. |
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