Interstate H-1

I-H1 Hawaii


Interstate H-1 is the longest of the four Hawaiian Interstates. The mostly urban freeway joins Makakilo City and the west shore of Oahu with Ewa, Waipahu, Pearl City, Downtown Honolulu and Waialae on the south shore.

The freeway provides the most direct route to Honolulu International Airport (HNL) and Hickham Air Force Base via the Hawaii 92 freeway spur. Interstate H1 includes the operation of the AM Contraflow Zipper Lane which provides an eastbound HOV lane during the morning commute hours in the place of two westbound lanes.

Route Information

  • West End – Honolulu

  • East End – Makakilo

  • Mileage – 27.16

  • Cities – Honolulu

  • Junctions – 

Source: December 31, 2018 Interstate Route Log and Finders List

1979 map showing the incomplete H1 freeway by Honolulu International Airport (HNL). The Moanalua Freeway (Hawaii 72 then) defaulted as the through route between Aiea and Honolulu at this time.

The I-H1 viaduct by Honolulu International Airport (HNL) was built over Hawaii 92 (Nimitz Highway). The freeway also overtook Hawaii 90 directly along the Kamehameha Highway.


Interstate H-1 was first authorized as a result of the Statehood Act of 1960.1 A portion of the freeway was completed in 1959 between Punahou Street (Exit 23) and King Street (Exit 25A). It was signed as Hawaii 72. A short extension followed in 1960 from Punahou Street west to Ke’eaumoku Street.

Interstate H1 signs were posted by 1967 along side Hawaii 72 and the Lunalilo Freeway. It was open from Kunia Road (Exit 5) to Kamehameha Highway (Exits 8A/B), from the east end of the Moanalua Freeway (I-H201) to Pele Street (Exit 21B), from King Street to Koko Head Avenue (Exit 26A). Completion of the route occurred in 1986 with the opening between Nimitz Highway (Exit 18A) and Middle Street. See the Interstate H1 guide on AARoads for a more detailed time line.

Freeway signs that showcase the name of Interstate H-1, the Queen Liliuokalani Freeway, were erected in 2002. The Queen Liliuokalani Freeway signs stand eastbound at Exit 1 and westbound after Exit 19. There are no similar name signs for the rest of H-1, which is called the Lunalilo Freeway.3

Some improvements made to Interstate H1 include adding auxiliary lanes, widening, and earthquake retrofitting. The Pearl City and Waimalu viaduct bridge deck was replaced by April 16, 2014. This work preceded restriping of the Halawa Interchange to the Pearl City off-ramp to add a shoulder lane during the evening peak hours and widening of I-H1 from the Pearl City ramps to the Waimalu viaduct. Widening also expands I-H1 westbound from I-H2 to Waikele, capping off expansion overall between Aiea to Waikele.4

Proposed Interstate H-4

Interstate H-4 was an idea once proposed for the city of Honolulu in the late 1960s. Interstate H-4 was to provide traffic relief for the congested Interstate H-1 through the downtown area of the capital city. From the west I-H4 was to begin at I-H1/Exit 18 interchange with Hawaii 92. Turning southeasterly, the freeway was to follow the Honolulu waterfront to a point somewhere between Atkinson Drive and Waikiki. At that location, Interstate H-4 was proposed to turn northeast to the Kapiolani interchange (Exit 25B) along Interstate H-1. As one can surmise, the idea of a freeway along the waterfront through Downtown was wildly unpopular and thus never realized.2

West End  – Makakilo, Hawaii


Ramps separate from Interstate H-1 eastbound beyond the transition from Hawaii 93 to Barbers Point and Makakilo City. Photo taken by Jeff Royston (02/01/06).

Signs posted at both ends of Interstate H-1 designated it as the Liliuokalani Highway. The eastbound assembly precedes the loop ramp for Farrington Highway, a local route east to Makakilo City and Waipahu. Photo taken by Jeff Royston (02/01/06).

west to

Westbound Interstate H-1 reaches Exit 1 for Farrington Highway east and Barbers Point Harbor. The freeway connects with Hawaii 93 north ahead of the intersection with Laaloa Street. Photo taken by Oscar Voss (11/01).

East End  – Honolulu, Hawaii

east to

Interstate H-1 concludes eastbound at the intersection with Ainakoa Avenue in eastern Honolulu. Hawaii 72 (Kalanianaole Highway) takes over from the freeway end along an at-grade boulevard. Photo taken by Oscar Voss (11/01).

west to

Hawaii 72 (Kalanianaole Highway) ends as Interstate H-1 (Lunalilo Freeway) begins westbound from the intersection with Ainakoa Avenue in Honolulu. Photo taken by Oscar Voss (11/01).


  1. History of Interstate H-3 by the Hawaii Department of Transportation
  2. Voss, Oscar. “Interstate H-4 proposal in the 1960s, and other Hawaii Highways site updates.” Online posting, misc.transport.road, September 17, 2003.
  3. Voss, Oscar. “Jeff Royston’s e-mail address, and minor comments on H-1 Interstate Guide.” Personal Email, 06/09/06.
  4. PM Contraflow – Overview, HawaiiDOT project web site.

Page updated July 8, 2015.