Windward Viaducts

The Windward Viaducts are twin concrete bridges running parallel to each other across the Koolau Range for several miles, carrying four lanes of Interstate H-3 traffic. These structures span across mountainous terrain to link Windward Oahu with central parts of the island.

The bridge was built using an innovative construction method that employed drilled piers instead of precast piles to reduce noise impact on the surrounding area. This project represented a major infrastructure step for Hawaii, enabling better connections between Windward and other parts of the island.

The viaduct design and construction methods demonstrate the Hawaiian commitment to preserving natural landscapes while developing necessary transportation infrastructure.

The viaducts carry daily traffic between Windward Oahu and the central areas, accessible via Interstate H-3. Drivers can expect typical highway conditions, though congestion may occur during rush hours.

The structure is made from precast cell box segments stacked to different heights, assembled like giant building blocks. This segmented construction method allowed faster assembly and reduced disruption during the mountain crossing project.