According to the U.S. Department of Transportation’s Federal Highway Administration (FHWA) website, “All but five State capitals are directly served by the Interstate System.” The five capital cities are: Juneau, Alaska; Dover, Delaware; Jefferson City, Missouri; Carson City, Nevada; and Pierre, South Dakota.

Legislation signed by President Eisenhower in 1960 “removed the limitation in Federal-aid highway law that the Interstate System be designated only within the continental United States,” thus both Hawaii and Alaska have designated Interstate highways (H-1, H-2, H-3 , H-4 and A-1, A-2, A-3, and A-4, respectively).


Bonus Question:
Which state has the most interstate miles:
Texas or California?

Answer: 
Texas, with 17 routes totaling 3,233.45 miles

(California has 25 routes
totaling 2,455.74 miles)