The following sites provide information on specific historic roads or regional systems and histories in the United States and abroad.

National/Transcontinental
http://www.lincolnhighwayassoc.org
Lincoln Highway Association

http://www.national66.com/
National Route 66 Federation

http://www.yellowstonetrail.org/
Yellowstone Trail, “From Plymouth Rock to Puget Sound”

Eastern United States
http://www.bostonroads.com/
Information regarding roads in metro Boston

http://merrittparkway.org/
Merritt Parkway Conservancy

http://www.nycroads.com/links/
Information regarding roads in metro New York City

http://mcmcweb.er.usgs.gov/phil/philhistory.html
Philadelphia area transportation history

http://www.phillyroads.com/
Information regarding road in metro Philadelphia

Central United States
http://www.ci.chi.il.us/Transportation/lsd/history.html
South Lake Shore Drive, Chicago, history

http://georgekessler.org/html/kessler/bio/Kcpb.html
Kansas City, Missouri, parkways

Southern United States
http://www.ashleyriver.org/history.html
Ashley River Road, South Carolina

Western United States
http://www.themilepost.com/history.html
History of the Alaska Highway

http://www.odot.state.or.us/hcrh/
Historic Columbia River Highway, Oregon

http://www.arroyoseco.org/asparkway.htm
Arroyo Seco Parkway, Los Angeles to Pasadena

http://www.denvergov.org/Parks_Recreation/349366template2jump.asp
Historic Denver Parkway system

International
The following sites provide information on historic roads throughout the world.

http://web.bham.ac.uk/leathepd/
Roman roads in Britain, (Birmingham project)

http://www.ess.uci.edu/~oliver/silk.html
The Silk Road (Asia)