H-1

About H-1

Also known as Queen Liliuokalani Freeway, Lunalilo Freeway.

From Kapolei, HI to Kahala, Honolulu, HI

Interstate H-1 is the longest and busiest Interstate Highway in Hawaii, running about 27 miles across the southern coast of the island of Oahu. It begins in the west near Kapolei at Farrington Highway and runs east through the urbanized corridor of central and southern Oahu, passing Pearl City and Aiea before threading through the heart of Honolulu and ending near Kahala on the eastern side of the city. As the principal commuter route on the island, it carries the heaviest traffic of any highway in the state.

The freeway is known as the Queen Liliuokalani Freeway on its western portion and the Lunalilo Freeway through Honolulu east of Middle Street. Near the airport it runs on elevated viaducts above the surrounding surface streets, and through the city it operates a weekday contraflow express lane that uses a movable concrete barrier to add capacity in the peak direction. It links the growing residential areas of leeward Oahu with the downtown business district, the airport, and the resort district of Waikiki.

Because Hawaii is not connected to the mainland Interstate network, H-1 and its companion routes carry an H prefix rather than a number tied to the national grid. H-1 is the spine of that small island system, feeding into both H-2 toward the center of the island and H-3 toward the windward coast.

State-by-state mileage

State	Miles
Hawaii	27.2
Total	27.2

History

Interstate H-1 was designated on August 29, 1960, after Hawaii became a state, and it incorporated an earlier section known as the Mauka Arterial that dated to the 1950s. Construction proceeded through the 1960s, with major segments opening in the second half of that decade, and the full route reached completion in the 1980s.

The highway qualified for Interstate funding because it served defense installations and the major population center of Oahu, the rationale that allowed the non-contiguous Hawaii routes to join the federally aided system.

Major cities and places

Notable features

• Eastbound weekday contraflow express lane with movable barrier
• Elevated viaducts near Daniel K. Inouye International Airport

Did you know

• It is the longest and busiest Interstate in Hawaii.
• It is the southernmost and westernmost signed Interstate in the United States.
• It was designated in 1960 and built largely through the 1960s.
• It runs entirely on the island of Oahu and connects to no mainland Interstate.
• It uses a movable barrier to create a peak-direction express lane on weekdays.