BELLINGHAM, Wash. — Drivers heading south on Interstate 5 near Bellingham should prepare for a new traffic pattern beginning Monday night as crews shift traffic onto a temporary bypass road for a major fish passage project.
Starting the night of June 15, southbound I-5 will move onto a temporary two-lane bypass at milepost 247, just south of Bellingham. The shift will allow construction crews to install a fish passage structure beneath the interstate.
The Washington State Department of Transportation said the speed limit through the work zone will drop to 50 mph and remain in effect until September.
Overnight Lane Reductions Planned
Drivers should expect southbound lane reductions and rolling slowdowns between 8 p.m. Monday and 5 a.m. Tuesday while crews complete the traffic shift.
WSDOT advises travelers to allow extra time and watch for changing traffic patterns through the construction zone.
The temporary bypass is part of Washington’s statewide effort to replace fish-blocking culverts and improve access to spawning habitat for salmon and other native fish species.
Long-Term Traffic Impacts Expected
While the overnight work will cause the most significant delays, motorists should expect reduced speeds and construction activity throughout the summer.
The project area sits near the stretch of I-5 south of Bellingham that has seen several major construction efforts in recent years, including emergency repairs following the March 2026 landslide near mileposts 248 and 249.
WSDOT has not announced additional full closures associated with the fish passage project, but drivers should continue to monitor travel alerts for future lane restrictions and construction updates.
Frequently Asked Questions
About the Author
