The following week, from 9 p.m. on Sunday, Sept. 18, to 5 a.m. on Thursday, Sept. 22, westbound I-90 will be reduced to one lane again as crews replace pavement on the right side.
Instead of paving over existing concrete, crews will remove all the concrete panels down to the dirt, then repave with asphalt.
Because of the volume of work needed, the repairs cannot be done only during overnight shifts.
WSDOT said the nearly 45-year-old concrete is cracked so badly that repaving over it is not an option.
“This section of I-90 is located near an old coal mine that was sealed up before the freeway was built. Through the years, water collected in the mine and began seeping under the westbound I-90 lanes. This softened the soil, which eventually led the concrete panels to crack,” WSDOT said in a news release.
The section of westbound I-90 carries about 29,000 vehicles a day. When traffic is forced down to one lane, drivers should expect backups or consider using public transportation, working remotely, carpooling or using another route.
KIRO 7 spoke with a commuter who said the backup was considerate and the 7-mile stretch between Snoqualmie and Issaquah took about two hours on Monday morning.
