Interstate H-201 supersedes Hawaii 78 along the Moanalua Freeway between the Halawa Interchange at Aiea and Kalihi by Fort Shafter Military Reservation. IH-201 lines all of the Moanalua Freeway with the exception of the western 0.7 miles between Kamehameha Highway (Hawaii 99) and the Halawa Interchange.
The urban freeway constitutes a commuter route between Downtown Honolulu and points along Interstate H1. The freeway also serves Aliamanu Military Reservation, Tripler Army Medical Center and Fort Shafter in addition to the Salt Lake area. Connections at the west end also provide direct access to Aloha Stadium.
The easternmost portion of the Moanalua Freeway was completed in 1959-60 and signed as Hawaii 72. This stretch, between Puuloa Road (Exit 3) and Middle Street, was renumbered to Hawaii 78 when Interstate H1 was designated. The remainder of Moanalua Road was upgraded to freeway standards during the 1980s.
This led to the Federal Highway Administration incorporating the freeway to the Interstate system on February 1, 1989.2 Hawaii submitted Interstate H-1A as the designation for the route to AASHTO on June 2, 1990. Action was withheld at that meeting. A subsequent application to AASHTO on December 8, 1990 resulted in the approval of Interstate H-201 instead of either Interstate H-1A or Interstate H-101.