The State Route 520 bridge will be closed this weekend from 11 p.m. Friday, Feb. 1, through noon on Sunday, Feb. 3.
Crews are working to install two overhead sign structures that will be wide enough to accommodate the highway when it is widened to six lanes.
Construction crews are also working to put together fiber optic lines to support the WSDOT's Intelligent Transportation Systems. While crews work to connect the new lines, the Seattle area traffic flow map will be offline.
During the closure, traffic on Interstate 90 will be heavier. To combat the increased traffic volumes, the I-90 express lanes will be open in the westbound traffic on Saturday, Feb. 2, from 7 a.m. to 2 p.m. The express lanes will switch to eastbound by 3 p.m.
To learn more about the project, visit the WSDOT website.