Highway in the Sky?

by Gregory Field

The Department of Transportation is considering implementing a plan to build a three level interchange at Castle Junction. In a preliminary study completed and presented to the public in 1990, three alternatives were described that would provide one or more overpass or underpass structures and ramps connecting Pali, Kamehameha and Kalanianaole Highways.

According to the Department of Transportation, from 1970 to 1990, average daily trips (ADT) near Castle Junction have increased 49% on Pali Highway, 89% on Kamehameha Highway, and 20% on Kalanianaole Highway. "The existing at grade intersection lacks the traffic carrying capacity to handle present and future peak hour travel demand."

Five alternatives are being considered:

Alternative A: Pali traffic from Honolulu would take a ramp and loop that passes under Kalanianaole Highway to access Kamehameha Highway Kaneohe bound. Access from Auloa Road would be limited.

Alternative B: All traffic movements to major highways are provided by direct ramps. Traffic from the Pali to Kaneohe passes over the intersection and traffic from Kaneohe to Kailua passes under the intersection.

Alternative C: A fully directional interchange, Pali to Kaneohe bound traffic access Kamehameha Highway via a two lane flyover. Kamehameha Highway traffic bound for Kailua pass under Kalanianaole Highway. A frontage road parallel to Kamehameha Highway would provide access to Auloa Road.

Alternative D: A broad range of potential improvement strategies referred to as Transportation System Management (TSM) would effectively capitalize on existing highway and transit facilities. Such measures include: ride-sharing (carpools), van pools, Public transportation, Flex-time work hours and intersection improvements.

Alternative E: A no build alternative assumes no improvements at Castle Junction.

The Department of Transportation has determined Alternative C the preferred alternative, with Alternative B ranked second. An Environmental Assessment has been prepared declaring no significant impact. Concerns have been raised that the interchange will have visual impact on the environment, the nearby War Memorial and the Kaneohe Ranch office which is considered architecturally and historically significant.

The Department of Transportation will hold public hearings on the interchange in January.