Work under way so northbound bridge can carry two lanes in each direction
ARLINGTON – Drivers will see big changes on Interstate 5 across the Stillaguamish River beginning Monday, July 7.
Later this month, contractor crews working for the Washington State Department of Transportation will begin work to replace the entire deck and some of the supporting steel framework of the southbound I-5 Stillaguamish River bridge. Both directions of traffic will use the northbound bridge while the southbound bridge deck is being replaced.
To keep traffic moving during construction, both directions of I-5 near the Stillaguamish River bridges will be reduced from three lanes to two. Concrete barriers will be installed along the northbound bridge’s centerline and median crossover lanes will be built to shift southbound traffic to the northbound bridge.
Lane reductions begin next week. The schedule is:
The bridges are located about 10 miles north of Marysville and about 19 miles south of Mount Vernon. With fewer lanes carrying the nearly 50,000 vehicles of each direction on I-5 across the Stillaguamish River, drivers could see delays of up to 35 minutes during peak travel times.
“If people can adjust their schedule a little during construction to avoid the peak travel periods, they can get to their destinations on time and help us keep traffic moving,” said WSDOT Northwest Regional Administrator Lorena Eng.
Once two-way traffic is established on the northbound bridge in mid to late July, heavy congestion is expected during the peak hours:
Because of the narrow shoulders, bicycles will not be allowed on I-5 between State Route 530/Pioneer Highway and 236th Street Northeast. A signed bicycle detour has been established west of the interstate via the Pioneer Highway and 236th Street Northeast.
About the bridge
The southbound I-5 Stillaguamish River bridge was built in 1933 as part of US 99. It originally carried two lanes in each direction and later became part of I-5 when the interstate was built in the 1960s. The northbound I-5 Stillaguamish River bridge opened in 1971. This allowed each direction its own bridge, improving safety and traffic flow on this section of I-5.