- United States Federal Highway Administration page with a collection of various auto trail, U.S. highway, and Interstates histories, some from older FHWA publications, as well as other related information.
- Catalog of auto trails from the United States and Canada in the 1910s and 1920s; includes route markers and current numbers.
Dixie Highway - - Guide to this eastern U.S. highway system of the early 1900s.
The Dixie Highway of North Georgia - - Tourism project for Cobb, Bartow, Gordon, Whitfield and Catoosa Counties in the U.S. state. Features history and maps.
Drive the Old Spanish Trail - - Contains history about and photographs of the former auto trail running along the southern tier of the U.S.
El Camino Real International Heritage Center - - Includes information about the El Camino Real de Tierra Adentro National Historic Trail, which traverses the country of Mexico and the U.S. state of New Mexico.
A Few Ghostation and Ghostroad Pix - - Description and photos of former US 80 through California and Arizona including the old plank road.
Historic Columbia River Highway - - Site covering the routing in Oregon, U.S. along the river in the general location of modern US 30 and Interstate 84. Includes activity information, pictures, postcards and ephemera scans.
Indiana's Historic National Road - - Covers that state's portion of the road from Illinois to Maryland, U.S. Includes history and attraction listing.
Interregional Highways - - Early plans for systems in the United States, some implemented, some not.
National Road Association of Illinois - - Organization focused on promoting the history of the first byway going west across America, currently known as U.S. Route 40. Includes history of the road, stories, membership details, and contacts.
Old Spanish Trail Centennial - - Organization involved in preparing the 2029 celebration of the auto trail. Includes history and travel log scans of the route.
Pete's Road Page - - Contains articles on Northwest Indiana, U.S., roads such as the Dunes Highway, the Chicago-Detroit Post Road, and the Lincoln Highway. Includes maps.
Roadsidephotos.sabr.org - - Contains information about U.S. 66 and the Lincoln Highway, including 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).
Travel on the Old National Road - - Activity page containing articles and links regarding this U.S. road, now mostly US 40. Part of an educational website about Abraham Lincoln.
Travel the Bozeman Trail - - A gold-rush trail cutting through the hunting grounds of the Northern Plains Indians in Montana and Wyoming, U.S.
US-27 in Michigan - - Includes some historic photographs and details about this route's former routing in the state, now supplanted primarily by US-127 and Interstate 69.
Via Egnatia - - Ancient Roman Road through the Balkan Peninsula of Europe. Includes map, links, and news.
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