People who rely on Interstate 5 through downtown Seattle should plan for significant lane reductions and an overnight closure as work to install a new electronic sign continues from Monday, Dec. 11, until Friday, Dec. 15, the Washington State Department of Transportation said. The electronic sign is another part of the I-5 Seneca to SR 520 mobility project , which also includes adding a third mainline lane near Seneca Street and ramp meters.

During this work, I-5 northbound will keep at least one mainline lane open from the I-90 interchange to Olive Way. The express lanes will remain open northbound. The collector/distributor ramp will close. The westbound I-90 to northbound I-5 ramp will close, and drivers should follow the signed detour. The Dearborn and Cherry street ramps will be close at 9 p.m.

Drivers can expect this work:

• From 10 p.m. Monday, Dec. 11, until 4 a.m. Tuesday, Dec. 12.
• Nightly from 10 p.m. Wednesday, Dec. 13, through 4 a.m. Friday, Dec. 15.

Travelers should prepare for a full northbound closure starting at 11:59 p.m. Tuesday, Dec. 12, through 4 a.m. Wednesday, Dec. 13. Northbound I-5 will close from the I-90 interchange to Olive Way. The express lanes will remain open northbound for drivers going north of downtown. The collector/distributorramp and the Dearborn, Cherry and University street ramps also will close at 11:59 p.m. Downtown drivers should exit by Edgar Martinez Drive.