The concrete paving on both I-405 and SR 518 was more than 40 years old. Years of heavy use on both roadways had resulted in severe cracks, bumps, and ruts. This project's scope aimed to produce a smoother drive—with better traction and new high visibility striping—by replacing damaged and broken panels, repaving sections, and grinding existing panels.

Crews completely replaced concrete pavement in all four lanes of northbound I-405 from SE 8th Street to just north of Main Street in Bellevue. In addition, crews ground the existing pavement across all lanes and replaced an additional 82 failing concrete panels on northbound I-405 just south of SE 8th Street and from Main Street to SR 520. Work also included hot mix asphalt (HMA) paving of inside/outside shoulders and the installation of traffic loops, striping, and drainage improvements. Drainage included catch basins and pipe installation at the median and at the northwest approach slab of the SE 8th Street Bridge.

Crews also improved nearly a mile of SR 518 pavement between I-5 and Sea-Tac Airport by replacing more than 50 concrete panels and using a diamond grinder to smooth out bumps and ruts on other areas of the highway. This work included installing data loops and striping on SR 518.

To minimize impacts to the traveling public, Atkinson performed the majority of the work on I-405 during two 54-hour weekend closures of northbound I-405 and on SR 518. During each I-405 closure, crews demolished two lanes (approximately 3,600 LF) of the existing PCCP pavement, removed unsuitable materials, placed and compacted subgrade materials, placed asphalt pavement underlayment and joint dowel bars, and repaved PCCP roadway sections.

Quantities totaled 6,288 cubic yards of PCCP paving, 5,059 tons of HMA asphalt paving, and 16,280 square yards (rough grade) and 4,687 tons (fine grade) of crushed surfacing base course (CSBC).