The I-5, I-405, SR 99 and SR 520 closures could cause backups beyond the freeway on surface streets and alternate routes not typically impacted by heavy traffic.

Southbound I-5 through Portland’s Rose Quarter will close Sept. 11 for up to five weeks, causing major delays as crews complete critical repairs.

Northbound I-5 is blocked at E. Sunset Drive in Bellingham Friday afternoon, the Washington Department of Transportation (WSDOT) confirmed.

The work is part of a series of projects designed to widen Interstate 5, WSDOT said.