Since the early 2000s, Interstate Guide has documented America's Interstate Highway System through photography, route histories, business routes, and reference material. The site covers both the familiar and overlooked parts of the national network.
Browse Interstate highways by route number or state, explore historical features and trivia, follow proposed corridors, and discover the stories behind the roads that connect the country.
Explore Interstate Guide
Browse Interstate routes, discover business loops, explore historical features, and follow the continuing evolution of America's highway network.
✓ Mainline Interstates
✓ Auxiliary Routes
✓ Future Interstates
✓ Former Routes
✓ Unsigned Routes
✓ Business Routes
Browse by Route Number
Interstate families and branch routes.
Browse by State
Routes organized geographically.
Business Routes
Former alignments and downtown connectors.
Features
History, trivia and numbering guides.
What's New
Recent additions and updates.
About Interstate Guide
Contributors and project history.
The Interstate Highway System has evolved substantially since the early years of completion. Today the system continues to grow with new corridors developed with Congressional authority, such as I-69 between Texas and Indiana, the completion of I-49 in Arkansas and Louisiana and the southern extension of I-27 from Lubbock to Laredo, Texas. Interstate Guide documents both the original network and the routes added through decades of expansion.
Interstate Guide currently documents:
Interstate Numbering Guide
Numbering guidelines for the Eisenhower Interstate System. Why is there an I-238 but no I-38? Read More →
Proposals and Unbuilt Routes
Previously proposed or suggested long distance and regional Interstate corridors that were never realized or otherwise remain unconstructed. Read More →
Recent Updates
Added photos of both ends of Interstate 564 in Virginia shot on July 29, 2025.
2026-08-26 17:08:07
Construction through Summer 2027 makes improvements at the south end of I-464 in Virginia including the addition of a flyover from I-64 along the inner loop of the Hampton Roads Beltway to SR 168 (Chesapeake Expressway) south. Update the page with photos of both ends from July 29, 2025.
2026-08-26 16:28:15
Updated coverage of both ends of Interstate 664 with photos from July 28th and 29th in 2025.
2026-08-26 14:36:24
Added a map scan from 1961 showing the initial proposed alignment of Interstate 64 following U.S. 50 and U.S. 150 across southern Illinois and Indiana. Updated content at the east end in Chesapeake, Virginia with photos from 07/29/25 showing new signage and the third westbound lane added along the Hampton Roads Beltway inner loop.
2026-08-26 08:09:15