Believe it or not, Hawaii does, indeed, have an interstate highway. Now, you ask, how can an island have an interstate highway? Well, U.S. law states that federal highway funds can be used as long as the proposed highway connects military bases. Oahuâ€™s Honolulu Highway, known to locals as â€œH1,â€ connects Pearl Harbor with Diamond Head, which used to be home to Fort Ruger. The first portions of the H1 opened in 1953, and over a half century later, H1 still enables locals and visitors alike to explore the beautiful island of Oahu. There are also interstates H2 and H3, which completed in 1997, has arguably some of the most beautiful views of any US highway.