Here are some interesting facts on Interstates across the nation.
Official Name: Dwight D. Eisenhower National System of Interstate and Defense Highways
Total Miles: 46,837 (2004)
Longest Interstate Routes:
I-90, Seattle, Washington, to Boston, Massachusetts, 3,020.54 miles
I-80, San Francisco, California, to Teaneck, New Jersey, 2,899.54 miles
1-40, Barstow, California, to Wilmington, North Carolina, 2,555.40 miles
1-10, Los Angeles, California, to Jacksonville, Florida, 2,460.34 miles
1-70, Cove Fort, Utah, to Baltimore, Maryland, 2,153.13 miles
Shortest Two-Digit Interstate Routes:
I-73, Emery to Greensboro, North Carolina, 12.27 miles
I-97, Annapolis to Baltimore, Maryland, 17.62 miles
I-99, Bedford to Bald Eagle, Pennsylvania, 53.00
I-19, Nogales to Tucson, Arizona, 63.35 miles
I-66, Strasburg, Virginia, to Washington, D.C., 74.80 miles
North-South Transcontinental Routes:
I-5 San Diego, California, to Blaine, Washington, 1,381.29 miles
I-15, San Diego, California to Sweetgrass, Montana, 1,433.52 miles
I-35 Laredo, Texas, to Duluth, Minnesota, 1,568.38 miles
I-55, New Orleans, Louisiana, to Chicago, Illinois, 964.25 miles
I-65, Mobile, Alabama, to Gary, Indiana, 887.30 miles
I-75, Miami, Florida, to Sault Ste. Marie, Michigan, 1,786.47 miles
I-95, Miami, Florida, to Houlton, Maine, 1,919.74 miles
States with Most Interstate Miles:
Texas, 17 routes, totaling 3,233.45 miles
California, 25 routes, totaling 2,455.74 miles
Illinois, 23 routes, totaling 2,169.53 miles
Pennsylvania, 22 routes, totaling 1,759.34 miles
Ohio, 21 routes, totaling 1,572.35 miles
States with Most Interstate Routes:
New York, 1,674.73 miles, 29 routes
California, 2,455.74 miles, 25 routes
Illinois, 2,169.53 miles, 23 routes
Pennsylvania, 1,759.34 miles, 22 routes
Ohio, 1, 572.35 miles, 21 routes
Routes Traversing the Most States:
I-95, 16 states (including Washington D.C.): Florida, Georgia, South Carolina, North Carolina, Virginia, Washington D.C., Maryland, Delaware, Pennsylvania, New Jersey, New York, Connecticut, Rhode Island, Massachusetts, New Hampshire and Maine
I-90, 13 states: Washington, Idaho, Montana, Wyoming, South Dakota, Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, New York and Massachusetts
I-80, 11 states: California, Nevada, Utah, Wyoming, Nebraska, Iowa, Illinois, Indiana, Ohio, Pennsylvania, and New Jersey
I-70, 10 states, Utah, Colorado, Kansas, Missouri, Illinois, Indiana, Ohio, West Virginia, Pennsylvania, and Maryland
I-10, eight states: California, Arizona, New Mexico, Texas, Louisiana, Mississippi, Alabama, and Florida
All but five state capitals are directly served by the Interstate System. Those that aren’t are Juneau, Alaska; Dover, Delaware; Jefferson City, Missouri; Carson City, Nevada; and, Pierre, South Dakota.
Oldest Segments: A portion of the Grand Central Parkway in Queens, New York, opened in 1936 and was later incorporated into the Interstate System as I-278; The Pennsylvania Turnpike between Irwin southwest of Pittsburgh and Carlisle west of Harrisburg opened in October, 1940, and is now I-76 and I-70.
Interchanges: 14,750 (approximate)
Bridges: 55,512 (as of December 2004)
Tunnels: 82 (104 bores)
Highest Elevation: Eisenhower Memorial Tunnel, Clear Creek/Summit counties, Colorado 11,012 feet (east) and 11,158 (west)
Lowest Elevation: Interstate 8, El Centro, California, 52 feet below sea level
Also of Interest: The FHWA's description of how the Interstate Highway System compares to Great Pyramid of Cheops in Egypt and the Great Wall of China.
The documents are provided in Acrobat Reader format. Free Acrobat Reader download 
