Feeling the traffic pinch in Issaquah: westbound I-90 to reduce to one lane in September

By Tom Pearce

We have a saying around the office: "There's no such thing as a simple paver." That's a reminder to us that even though a project may seem pretty basic, the effects on travelers may not be so easy to navigate.

Beginning Sunday night, Sept. 11, we'll begin a project that no one ever considered a simple paver – we'll reduce a three-lane section of westbound I-90 just east of Issaquah to one lane for three consecutive days and four nights. Around-the-clock work will begin at 9 p.m. Sunday, Sept. 11, and continue through 5 a.m. Thursday, Sept. 15, while we replace the concrete panels on the left side of I-90. The lane reduction provides a safe work area for the people repairing I-90.

The following week, from 9 p.m. Sunday, Sept. 18 to 5 a.m. Friday, Sept. 23, we'll reduce westbound I-90 to one lane again as crews replace pavement on the right side.

When paving asphalt on soil, it takes a few layers to create the designed thickness.

There's nothing simple about repaving a 1,550-foot section of I-90, particularly when we need to reduce a three-lane section of freeway to one lane. In this case, we're not just paving over the top of existing concrete, we're removing all of the concrete panels all the way down to the dirt, then repaving with asphalt. The amount of work necessary means we cannot do this only during overnight shifts.

We need to do this because the nearly 45-year-old concrete is cracked to the point where repaving 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.

Water that has collected in an old mine now seeps under westbound I-90 east of Issaquah.

In addition to the paving work, this project includes drainage improvements to reduce the amount of water that goes under I-90.

This section of westbound I-90 carries about 29,000 vehicles a day. When all three lanes are open, it's generally a free-flowing stretch. Forcing all traffic into one lane is going to create backups, particularly at peak hours. You may be able to help reduce the number of vehicles on the road by:

• Using transit
• Carpooling
• Working from a remote location
• Avoiding westbound I-90 during morning commute hours

We understand these solutions won't work for everyone, but people who can choose one of these options will spend a bit less time sitting in traffic. If enough people do something different, we can limit backups for everyone.

More work on westbound I-90 planned

This repaving work is only part of the project. We will have additional multi-day closures to repave a bridge and replace the approach to another bridge west of Preston. Each of these projects will require us to reduce I-90 to a single lane. When we have dates for this work, we'll let you know.

Repaving the Highlands Drive on-ramp

It's part of a separate project, but we expect to complete the paving in the next week on the Highlands Drive Northeast on-ramp to westbound I-90.

While our crews and contractors can make the work look easy, it's never simple. We appreciate your understanding as we finish this work as safely and quickly as possible.