Interstate H-1


Interstate H-1 is the longest and busiest Interstate Highway in the US state of Hawaii. The highway is located on the island of O‘ahu. Despite the number, this is an east–west highway; the 'H'-series numbering reflects the order in which routes were funded and built. H-1 goes from Route 93 in Kapolei to Route 72 in Kāhala. East of Middle Street in Honolulu, H-1 is also known as the Lunalilo Freeway and is sometimes signed as such at older signs in central Honolulu. West of Middle Street, H-1 is also known as the Queen Liliuokalani Freeway; this name is shown on some roadmaps. It is both the southernmost and westernmost signed Interstate Highway in the United States.

Route description

Interstate H-1 begins near the Campbell Industrial Park in the town of Kapolei, Hawaii. West of this point, Hawaii State Route 93 continues toward Waianae. The freeway continues east, passing the community of Makakilo until reaching the junction with SR 750 and SR 76.
H-1 then continues along the northern edge of Waipahu approximately until its junction with Interstate H-2. It then continues east through the towns of Pearl City and Aiea for approximately to the complex Halawa Interchange, where it meets Interstates H-3 and H-201. The highway then turns south for two miles, then east soon after the exits for Hickam Air Force Base and Pearl Harbor. At this point, the highway runs along a viaduct above State Route 92, passing to the north of Honolulu International Airport.
Two miles past the airport exit, three lanes exit the freeway at exit 18A to join Nimitz Highway toward Waikiki, while half a mile later the remaining two lanes make a sharp turn south as H-1 reaches another major interchange with the east end of Interstate H-201. Access is provided by a left exit from H-1 east only. H-1 west does not have access to H-201 at this point.
From here H-1 runs through the city of Honolulu along a series of underpasses and viaducts. A flyover interchange leading to downtown Honolulu has a westbound exit and an eastbound entrance. H-1 ends in the Kahala district of Honolulu near Kahala Mall, where State Route 72 ends.
During morning commute hours on weekdays, an eastbound contraflow express lane is deployed from just west of exit 7 to exit 18A, where it connects to the beginning of the Nimitz Highway contraflow lane. The H-1 contraflow lane is often referred to as a "zipper lane" due to the use of a movable concrete barrier and a zipper machine. The H-1 and Nimitz Highway contraflow lanes are restricted to buses, motorcycles, and vehicles with two or more occupants while in operation.

History

Interstate H-1 was authorized as a result of the Statehood Act of 1960.
The portion of H-1 that runs through downtown Honolulu opened in 1953 as the Mauka Arterial; it was added to the Interstate system when Hawaii became a state. This section has been largely unchanged since its inception and its design suffers from having too many on/off ramps, short distanced on-ramps, and on-ramps that enter the freeway almost immediately before an off-ramp. The 'new' section of H-1 was, however, built to modern freeway standards.
The Hawaiian Interstate shields have gone through several changes. Early shields contained the hyphen as per the official designation ; however, these shields have been updated with the hyphen removed. As in other states across the contiguous United States, early interstate shields also included the writing of 'Hawaii' above the interstate route number and below the 'Interstate' writing. While the "Queen Liliuokalani" section of the Interstate H-1 has signs designating it as such, there are no similar name signs for the Lunalilo Freeway portion.

Interstate H-4

In the 1960s a fourth freeway that would have been Interstate H-4, was proposed for the city of Honolulu. The intent of H-4 was to provide relief to the congested H-1 through downtown Honolulu. Had it been built, the route of H-4 would have started at exit 18 and followed the Honolulu waterfront to the Kapiolani interchange. The idea, however, was unpopular and the freeway was never built.

Exit list

Auxiliary routes