Drivers should plan ahead for delays when the SR 520 drawspan opens tonight for boat traffic.

Washington State Department of Transportation bridge crews will open the bridge at 9 p.m. to allow a construction barge to pass through. The opening will last approximately 30 minutes.

Drivers will be alerted to possible 30-minute delays by electronic signs on highways that lead to the bridge. Drivers can take I-90 across Lake Washington to avoid delays.