I-5, Mounts Rd to Steilacoom-DuPont Rd – Corridor Improvements

Contract summary

The project provides for the improvement of I-5, from milepost 116.55 to 120.94, Pierce County. I-5 will be widened to accommodate four thru-lanes in each direction. Auxiliary lanes will be added to both directions of I-5 between the Center Drive and Steilacoom-DuPont Road interchanges. The left lane in both directions of I-5 will be striped as a high occupancy vehicle (HOV) lane.

The Steilacoom-DuPont Road interchange will be reconstructed to provide grade separation over the Sound Transit railroad and maintain access to the Joint Base Lewis-McChord (JBLM) DuPont Gate. A shared use path within the new interchange will provide non-motorized connectivity between the JBLM DuPont Gate and the City of DuPont.

A roundabout will connect Steilacoom-DuPont Road and Wilmington Drive with the reconstructed interchange. Improvements within the JBLM secure perimeter include lowering Pendleton Avenue under I-5 and the Sound Transit railroad bridge, landscape restoration within the Memorial Arboretum, constructing a new historical marker and vehicle pullout along Pendleton Avenue, and two noise walls.

Other major work includes utility relocation, earthwork grading, bridge construction and demolition, retaining walls, storm water management facilities, concrete barrier, guardrail, hot mix asphalt (HMA) paving, illumination, traffic signals, intelligent transportation systems (ITS), signing, and overhead sign structures.