From a press release:

Nighttime and early morning drivers on Interstate 405 in Bellevue, Kirkland and Bothell should prepare for possible delays this weekend.

Contractor crews working for the Washington State Department of Transportation will close several I-405 lanes and ramps tonight, Friday, as well as Saturday and Sunday nights, between State Route 520 and State Route 522. These closures are needed to complete paving, striping and barrier work for the I-405 Bellevue to Lynnwood Widening and Express Toll Lanes project.

A detailed listing of closures is available on the I-405 Construction Update page at http://www.wsdot.wa.gov/Northwest/King/Construction/I405.htm

This work is weather dependent and is subject to change. Signed detour routes will be displayed for the ramp closures.