Interstate H-201 supersedes Route 78 along the Moanalua Freeway between the Halawa Interchange at Aiea and Kalihi by Fort Shafter Military Reservation. IH-201 follows all of the Moanalua Freeway with the exception of the western 0.7 miles between Kamehameha Highway (Route 99) and the Halawa Interchange.
The urban freeway constitutes a commuter route between Downtown Honolulu and points west 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 Route 72. This stretch, between Puuloa Road / Exit 3 and Middle Street, was renumbered to Route 78 when Interstate H1 was designated. The remainder of Moanalua Road was upgraded to freeway standards during the 1980s.
Subsequent action by the Hawaii Department of Transportation on April 6, 1988 requested the Federal Highway Administration (FHWA) for the addition of a 4.1 mile segment of SR 78 along the Moanalua Freeway to the Interstate system under the provision of 23 U.S.C. 139(a). The requested addition was to be numbered as H-1A. FHWA concurred with the request on November 1, 1989, citing that the entire route met Interstate standards with the exception of the Middle Street Interchange where SR 78 meets I-H1. The route number H-1A was assigned subject to approval from the American Association of State Highway and Transportation Officials (AASHTO) Route Numbering Committee.
The Hawaii Department of Transportation submitted an application to AASHTO on May 18, 1990 for the establishment of Interstate H-1A for the 4.1 mile long portion of the Moanalua Freeway. Action on the request was withheld at the meeting on June 4, 1990 and explained in a letter sent to the Hawaii Department of Transportation from AASHTO on June 14, 1990:
After the Committee discussed the application with Chief Engineer Tetsuo Harano, they decided to withhold action on the application so that further review could be made by Hawaii and the Federal Highway Administration on the proposed Interstate Route.
FHWA followed up with AASHTO related to the Interstate route numbering of the Moanalua Freeway on June 18, 1990:
We understand the AASHTO Route Numbering Committee that met on June 2 withheld approval of the State of Hawaii’s request to assign the Interstate route number H-IA to the Moanalua Freeway. The FHWA approved the addition of the Moanalua Freeway to the Interstate System on November 1, 1989, under 23 U.S.C. 139(a), Additions to the Interstate System. Our principle concern at the time was the qualification of the facility as a logical addition to the Interstate System, not the specific numbering of the route per se.
We recognize that the AASHTO route numbering policy does not subscribe to new divided route numbering such as Interstate 35E and 35W and we support that policy. The addition of the Moanalua Freeway to the Interstate System constitutes a loop from H-l; therefore, a three-digit number may be suitable.
We will ask the State to reconsider the route numbering. We appreciate the opportunity to comment to AASHTO on proposed
Interstate route numbering.
FHWA then suggested to the Hawaii Department of Transportation:
Therefore, other options to the H-IA numbering may be a three-digit number. For example, H-201, because the approved Interstate segment constitutes a loop from Interstate H-1. We would not object to a three-digit number; however, it would, of course, be subject to approval by the AASHTO Route Numbering Committee.
Hawaii submitted a new application to AASHTO for the establishment of Interstate H-101 along the Moanalua Freeway on October 16, 1990. The Route Numbering Committee approved the request on December 7, 1990, but instead as Interstate H-201. Correspondence from AASHTO to the state of Hawaii on December 14, 1990 explained the change:
The Interstate Route was approved as H-201 instead of H-101 as submitted because this route constitutes a loop, and the Committee felt that a three-digit number beginning with an even digit was more suitable. The Federal Highway Administration has concurred with this request.