More than 60,000 people a day must find another way to cross the Lake Washington Ship Canal, where state repair contractors are closing the Montlake Bridge for the next four weeks.

They’ll replace two-decade-old steel decks that required urgent patching on nine occasions last year, according to project engineer Hung Huynh. Montlake Bridge was built in 1925.

The 26-day construction project begins at 11:59 p.m. Sunday and continues until 5 a.m. on Friday, Sept. 3, allowing traffic to return just in time for the Labor Day weekend.

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The roughly 61,500 cars and trucks per day that cross the bridge must soon detour to Interstate 5 or other roads that span the waterway.

“This preservation project will keep the bridge in a state of good repair, as it continues to support the needs of a growing population,” says a Washington State Department of Transportation statement.


Pedestrian and bicycle paths will remain open. Ambulances will be allowed to cross.

Sound Transit’s light-rail station at the University of Washington is recommended as a hassle-free option, with trains arriving every eight to 10 minutes most times of day.

UW Medical Center‘s Montlake Campus and Sports Medicine Center at Husky Stadium, and nearby Ravenna and Roosevelt clinics, are open for all services — but patients need to allow extra travel time, or take light rail, managers say. Parking facilities will be open as usual.

August construction detours will affect 5,000 bus riders a day whose routes cross the Montlake Bridge, said Al Sanders, spokesperson for King County Metro Transit.

Crosstown routes 43 and 48 will switch to the University Bridge, going from Campus Parkway Northeast to Eastlake and Capitol Hill. Highway 520 buses serving the University District will skip the Montlake interchange, and exit 520 at East Roanoke Street, continuing via surface roads to the university.

Boats can still travel Montlake Cut, where bridge tenders can open one leaf of the drawspan. But larger boats must provide 24-hour notice to request a double-leaf opening. Vessels less than 30 feet high can pass while the decks are down.

While the bridge is being repaired, WSDOT will reduce other lanes nearby for work on its Highway 520 Montlake interchange. Crews will excavate and replace petroleum-contaminated soil from a former gasoline station.

The $7.4 million bridge project continues through the fall, during five weekends when the UW football team isn’t playing at home. On those days, crews will replace mechanical parts as the decks stay upright — blocking not just motorists, but bicyclists and pedestrians.