Interstate H-1 (or H-1) is the most important interstate highway in Hawaii, United States, located on the island of O‘ahu. The road sees more traffic than any other interstate in Hawaii. Despite the number, this is an east-west highway–the 'H'-series (for Hawaii) numbering is done in the order in which routes were given money and built. H-1 goes from Route 93 (Farrington Highway) in Kapolei to Route 72 (Kalanianaole Highway) in Kāhala. East of Middle Street in Honolulu (exit 19A), H-1 is called the Lunalilo Freeway and is sometimes signed as such at older signs in the center of Honolulu. West of Middle Street, H-1 called the Queen Liliʻuokalani Freeway; this name is shown on some roadmaps. It is the west-most interstate highway in the United States. The route is 27.16 miles (43.71 km) long.