The Mamalahoa Highway Widening project was initiated to widen Mamalahoa Highway on the east side of Waimea. Sections of the highway were eroding and on unstable ground; portions of the roadway needed full reconstruction. Additionally, the project aimed to improve the flow of traffic on Mamalahoa Highway through the addition of turn lanes and wider shoulders, including significant modifications to storm drainage structures that impacted the quality of the roadway.
GBI’s scope of work included full reconstruction and shoulder widening over a significant portion of this 5-mile stretch of heavily trafficked roadway. GBI also replaced 1,500 feet of waterline, installed new drain lines, and built retaining walls. The new waterline is intended to prevent future leaks or breaks in a line that supplies most of the area’s water, while the new drain lines are intended to prevent flooding into properties adjacent to the highway. Mamalahoa Highway is one of the busiest roadways on the island; therefore, GBI’s field and management teams worked closely with the client and the Waimea community to ensure that any safety- or traffic-related issues were resolved in a timely and professional manner. Additionally, crew members had to contend with variable weather conditions, including rain and fog. The crew adapted to the constant weather changes and took full advantage of dry conditions.