Planning a trip to or through Lynnwood this weekend? You might want to consider a backup plan  – or prepare for delays.

The Washington State Department of Transportation sent a reminder Friday that it is closing the southbound I-5 on-ramps from SR 525 and I-405 from Friday night to Monday morning, Sept. 23 through 26, while crews complete new on-ramps and connect them to the southbound lanes. Northbound I-405 drivers will be detoured to southbound I-5 via the 164th Street SE interchange. To avoid backups on this route, consider taking alternate routes like SR 522, SR 527, SR 524 and SR 104 to reach southbound I-5.

If you’re on southbound SR 525, you can take southbound SR 99 to 196th Street Southwest or 220th Street Southwest to reach southbound I-5, the DOT says. You can also reach southbound I-5 via Alderwood Mall Parkway and westbound 196th Street Southwest

The new on-ramps will open at 5 a.m. Monday, Sept. 26, but there will be more changes next week as well. A temporary traffic island will separate mainline I-5 traffic from on-ramp traffic and traffic exiting to 196th Street Southwest for five days while crews work to complete the new 196th Street Southwest off-ramp. “If you’re on southbound I-5 and need to exit to 196th Street SW, you’ll need to move into the right lane prior to the I-405 interchange to avoid missing the exit,” the DOT said.

The new off-ramp to 196th Street Southwest will be opened on Friday morning, Sept. 30. Visit the website to get an overview of what the change will look like, and check out the Snohomish County construction page for a detailed listing of ramp and road closures.

By the end of the month, drivers will use new on- and off-ramps designed to eliminate lane-weaving and reduce the risk of collisions.