Union Hill Road/SR 520/Avondale Road

Location: Redmond

Owner/developer: City of Redmond

Project team: Gary Merlino Construction, general and concrete contractor; INCA Engineers, structural engineer; Cadman, ready-mix supplier

Improvements to the Northeast Union Hill Road/SR 520/Avondale Road Northeast intersection were completed on a fast-track schedule over two weekends. The intersection handles about 59,000 vehicles a day, including a significant number of trucks. Its 6- to 12-inch asphalt pavement had a history of failures and rutting.

The city’s challenge was to replace the asphalt with more durable concrete, increase the capacity of the intersection in its limited footprint and keep traffic flowing as smoothly as possible. Specifications called for replacing the pavement in weekend closures that started at 8 p.m. Friday and ended at 5 a.m. Monday.

The first phase reconstructed the east half of the intersection. The job included breaking up and removing 2,500 cubic yards of asphalt and dirt; hauling, placing and grading 1,800 tons of crushed base course; and placing 1,400 cubic yards of 10-inch concrete pavement.

Phase two focused on the west half of the intersection. It included breaking up and removing 1,800 cubic yards of asphalt and dirt; hauling, placing and grading 800 tons of crushed base course; and placing 460 cubic yards of concrete pavement by hand.

Work over both weekends was completed in time for Monday morning traffic.