Construction will force slowdowns, detours or lane changes on westbound I-90 at Mercer Island, Highway 18 through Auburn and I-5 along the Tulalip Tribes business area.

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Freeway drivers in Bellevue, Marysville and Auburn will run into construction delays this weekend, including a squeeze into the Interstate 90 express lanes westbound across Lake Washington.

So plan for detours and delays:

• Westbound I-90 will be reduced to one lane at Bellevue Way Southeast, then funneled into the express lanes at Mercer Island, from 11 p.m. Friday until 5 a.m. Monday.

This is part of the ongoing retrofit of Mercer Island lids and Mount Baker tunnels, to add carpool and bus lanes and new fire-suppression equipment. The added lanes, part of a $188 million project, are a precondition for Sound Transit to take over the express lanes in 2017 to construct the East Link rail line.

• Highway 18 will close eastbound at Auburn-Black Diamond Road, forcing traffic to detour there. Crews will replace 500 feet of cracked pavement near the Neeley Bridge, which crosses the Green River, where an early December rainstorm damaged the roadway.

The detours last from 11 p.m. Friday until 5 a.m. Monday. State officials say slowdowns could spread to interstates 5 and 405, as drivers bypass the Auburn area.

• At Marysville, two left lanes of northbound I-5 will close Saturday night until Sunday morning. And the left southbound lane will close overnight as well. The first closures begin at 7:30 p.m., with all lanes reopened by 10 a.m.

Concrete-bridge columns will be poured in the median for the Tulalip Tribes project to expand the I-5/116th Street Northeast interchange, which carries traffic to the tribes’ retail-outlet mall and resort casino.

Looking ahead, sign installations on Aurora Avenue North, in the South Lake Union area, will cause seven weeks of lane reductions starting Jan. 18. The greatest impact will likely be longer transit trips, as the southbound bus lane will be open to general traffic.