Interstate H-1
| H-1 highlighted in red | ||||
| Route information | ||||
| Maintained by HDOT | ||||
| Length | 27.16 mi (43.71 km) | |||
| Existed | 1960–present | |||
| History | Completed in 1986 | |||
| NHS | Entire route | |||
| Major junctions | ||||
| West end | Route 93 in Kapolei | |||
| East end | Route 72 in Honolulu | |||
| Location | ||||
| Country | United States | |||
| State | Hawaii | |||
| Counties | Honolulu | |||
| Highway system | ||||
| 
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Interstate H-1 (H-1) is the longest (27.16 miles = 43.71km) and busiest Interstate Highway in the US state of Hawaii. The highway is located on the island of Oʻahu. Despite the number, this is an east–west highway; the 'H'-series (for Hawaii) numbering reflects the order in which routes were funded 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 also known as the Lunalilo Freeway, after the former Hawaiian king, and is sometimes signed as such at older signs in central Honolulu. West of Middle Street, H-1 is also known as the Queen Liliʻuokalani Freeway, after the former Hawaiian queen; this name is shown on some roadmaps. It is both the southernmost and westernmost signed Interstate Highway located in the US.