Demolition crews are gearing up to take down the old Evergreen Point Road overpass above State Route 520 in Medina, which requires closing the highway and floating bridge between Seattle and Bellevue this weekend.

During the closure, drivers will have to find another way across or around Lake Washington from 11 p.m. Friday, March 9, until 5 a.m. Monday, March 12. All lanes and ramps will be closed between Montlake Boulevard in Seattle and Interstate 405 in Bellevue. Alternate routes could see traffic delays midday Saturday and Sunday.

The narrow two-lane overpass was built in 1962 to carry local Medina traffic over SR 520. Crews estimate they will stockpile and later haul out up to 50 dump trucks of concrete overpass debris to the Cadman recycling yard in Redmond.

During this weekend’s construction about 100 construction workers will focus on demolition and other highway work. Once the Medina overpass is gone, crews will shift gears to build new concrete supports for the new Evergreen Point Road lidded overpass, which will be completed during the next 18 months.

While SR 520 is closed for the weekend, traffic is expected to be heavy midday Saturday and Sunday on I-5 and I-90 heading into Seattle and on I-405 approaching I-90. The express lane schedules will change this weekend on I-90 to maintain traffic flow.