Drivers should plan ahead for delays on state Route 900 this weekend as crews replace a culvert south of Talus Drive.

Flaggers will alternate one-way traffic on SR 900 from Talus Drive to Southeast 82nd Street from 8 p.m. Friday, Sept. 11 to 5 a.m. Monday, Sept. 14 while crews finish replacing the culvert at the West Fork Tributary to Tibbett’s Creek, just south of Talus Drive.

Drivers can expect significant backups during the work and should choose alternate routes when possible.

Crews replaced the western half of the West Fork Tributary culvert in early August.

They also replaced the culvert at Clay Pit Creek during a full weekend closure last month.

This work is part of the SR 900 Newport Way to SE 78th Street widening project. For more information, visit the project Web site: www.wsdot.wa.gov/Projects/SR900/SE78th_Issaquah.