Second and final stage of I-5 widening project underway

Night time lane closures begin Monday, Aug. 26.

CENTRALIA – Travelers on Interstate 5 in Centralia will see construction crews on the roadway next week as the second and final stage of widening work picks up pace.

Drivers can expect night time lane closures, traffic shifts and roadside work starting Monday, Aug. 26. Lane closure hours will vary depending on days of the week and traffic conditions. Drivers will typically encounter closed lanes on the interstate from 8 p.m. to 5 a.m. on weekdays, and 10 p.m. to 8 a.m. weekends.

“Our contractor is jumping in with both feet this summer,” said Washington State Department of Transportation project engineer Colin Newell. “Drivers will see changes to I-5 pretty quickly and a bunch of activity along the interstate, especially at Blakeslee Junction and Mellen Street.”

Crews working just north of Harrison Avenue will lay the foundation for new I-5 lanes that will connect to the recently completed southbound I-5 bridge over Blakeslee Junction. The lanes and southbound bridge will carry I-5 traffic while crews demolish the existing Blakeslee Junction bridges and build the new northbound structure.

I-5 drivers can expect narrow and shifted lanes until the new northbound bridge is complete in 2015.

Two miles to the south at Mellen Street, workers will start building a new bridge over I-5 late this summer. The bridge is part of a “couplet system” at the Mellen Street interchange that will create a circular flow of traffic across I-5 and help improve access to southern Centralia.

The couplet system is a priority for Scarsella Bros., WSDOT’s contractor for Stage 2 of the widening project. The new bridge has to be complete and the existing Mellen Street interchange reconfigured before crews can open the Louisiana Avenue-Airport Road connection to traffic in late 2014.

“Without the couplet system, adding traffic from the Louisiana Avenue-Airport Road connection will just make congestion at I-5 and Mellen worse than it already is,” said Newell. “When the couplet is done, traffic will flow on Mellen and across I-5 more efficiently, helping the interchange handle more traffic.”

The I-5, Mellen Street to Blakeslee Junction project is scheduled to be complete in late 2015. It is the last project in an eight-year-long, $168 million effort to improve safety and congestion on I-5 in Lewis and south Thurston counties.

Drivers can stay up to date on project developments by signing up for email updates, or visiting WSDOT’s travel alerts and construction update Web pages: