The second weekend of back-to-back bridge repairs will close three northbound lanes of I-5 over the Duwamish River.
The closure of the three left lanes is scheduled to begin at 10 p.m. Friday and end at 11:59 p.m. Sunday. It will stretch from the I-405/Highway 518 interchange to Martin Luther King Jr. Way.
The on-ramps from Southcenter Boulevard and Interurban Avenue South in Tukwila also will close, to avoid adding cars to mainline lanes that are going to be crammed.
The I-405 HOV bypass ramp to northbound I-5 will be closed, but the general-purpose merge from I-405 onto I-5 will be open. Drivers arriving from Sea-Tac Airport on the downhill Highway 518 offramp can merge onto the left side of northbound I-5.
An exit lane from northbound I-5 to northbound Highway 599 will stay open.
State advisories don't show a specific detour route because there are several options depending on your destination. Drivers often shift to Highway 167 or Highway 181 heading north through Kent and Renton to reach I-405 and Bellevue.
The partial closure is to fix old steel parts of expansion joints that are a half-century old and began to fail in the fall. State officials left them in place last June during a repave, saying they appeared to be in good shape at that time.
The repairs could be postponed if rain falls.
This weekend's work is part of the multiyear Revive I-5 program, which this year includes repaving northbound lanes from Tukwila to Seattle's Roosevelt neighborhood, and southbound lanes from Spring Street to the Georgetown area.