Thursday, October 4, 2018

Lots of I-5 rehabilitation in King County planned during next decade

By Tom Pearce

We’ve made great progress to Revive I-5 in the Seattle area this year, but we still have one more weekend-long lane closure on northbound I-5 set for Oct. 13-14. After that, we plan to complete the rest of the work during overnight shifts.

I wish I could tell you that this is the last of the major closures on I-5 for a few years, but that’s not the case. Parts of I-5 are almost 60 years old now, and most have had only routine maintenance. As we’ve been saying about projects for the past few years, it’s time for a major rehabilitation effort. So far, we’ve completed major repairs on I-5 northbound and southbound south of Seattle.

Those are a good start, but it’s only the beginning. In the next 10 years, in King County alone we have more than 25 projects that are planned. This includes more than a dozen paving and expansion joint projects in both directions of I-5 in King County and more than a dozen safety and maintenance projects.
More than two dozen projects are proposed to Revive I-5 in King County during the next 10 years.
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And this is only the work on I-5 in one county. We’ll continue doing projects on highways across Washington to keep them in a state of good repair.

Here’s just a sample of the work that will Revive I-5 in King County during the next decade if funding is provided:
  • We have southbound projects to replace aging expansion joints and paving the bridge decks.
  • We will replace more than 4 miles of concrete across all lanes in both directions of I-5 between 117th Street and the Ship Canal Bridge. This can’t be done with just weekends. It will require weeks of lane closures, similar to a project we did on northbound I-5 south of Seattle in 2007. We’ll only work in one direction at a time, but people are going to want to use alternatives.
  • We’ll repave both directions of the I-5 Ship Canal Bridge, which will require extended lane reductions.
  • We have several projects that will replace damaged concrete panels, grind concrete to eliminate ruts and repave asphalt. These may require weekend-long lane reductions. 
  • We have five projects planned that will reinforce key bridges and overpasses to withstand earthquakes.

You may look at this and think, “Wow, that’s a lot of work. Why did you put it off until now?” I-5 has held up much better than the original designers expected. When the interstate in Seattle opened, its estimated pavement lifespan was 25 years. The concrete pavement reached well into its 40s before it began showing signs that it would need major rehabilitation.
While plenty of work has been done to Revive I-5 in the Seattle area over the past couple years, a lot more work is planned for the highway in King County over the next decade.
Our engineers closely follow the condition of the interstate – and all state highways – and make decisions about which areas are most in need of repair, and which can wait. We don’t have a full schedule for all of the work needed during the next 10 years, but our team will prioritize the work based on the condition of the highway and available funding.

It will take another 10 years, but when we complete these needed repairs, I-5 in King County will be in good condition for decades to come.