Thursday, April 25, 2019

SR 18 project will smooth westbound Issaquah-Hobart Road overpass

By Tom Pearce

If you've driven across the westbound State Route 18 overpass at Issaquah-Hobart Road, you probably know exactly why it needs to be repaved. But if you haven't, the satellite view below shows why. There are so many patches, it's hard to count – let's just say about 40 to 50, ranging in size from a few inches across to more than 10 feet long.
Just a few of the patches that dot the westbound SR 18 overpass at Issaquah-Hobart Road.

All those patches create a rough and bumpy ride for travelers in the 12,000 vehicles who use this section of highway each day. That's part of the reason why we're going to resurface the bridge starting Monday, May 13. The other is that we need to maintain our aging state highways so they can continue to serve the traveling public. But in order to complete the work safely, there will be more than two months of around-the-clock traffic adjustments through this area.

Around-the-clock work
The Issaquah-Hobart Road overpass is located about a half-mile west of where westbound SR 18 widens from one lane to two; the bridge is two lanes wide. When work begins, our contractor crews are simply going to extend the one-lane section to the west end of the bridge. This will allow crews to repave the closed lane, then shift traffic onto the freshly paved lane and repave the other lane. The work will occur around-the-clock for approximately 65 days.
When work begins on May 6, westbound SR 18 will remain one lane until
the west end of the Issaquah-Hobart Road overpass for 65 days.

The bridge was last paved in 1989. To create a more durable surface, our contractor crews will remove the old pavement, make any necessary repairs to the bridge deck, then repave it with concrete.

Overnight full closures
While we can keep one lane of the highway open through most of the bridge work, our contractor crews must close both westbound lanes for up to eight nights in order to pour the new driving surface. During these overnight full closures, traffic will bypass the bridge by using the Issaquah-Hobart Road off- and on-ramps, with a uniformed police officer directing traffic at the intersection.

Strengthening our highways
The 30-year-old driving surface across this overpass is worn to the point that it needs to be replaced. The many years of fluctuating weather, the growing number of vehicles using the roadway and heavy loads from freight have caused extensive wear and tear on the bridge deck. In addition to providing a smoother ride, these repairs will help preserve and protect the bridge structure and reduce the need for costly emergency repairs.

While we're resurfacing the westbound bridge, our contractor crews will continue work to repave more than four miles of eastbound SR 18 between Southeast 304th Street in Auburn and Southeast 256th Street in Covington.

All of this work is part of our ongoing efforts to maintain and preserve our aging state highways. Thank you, as always, for your patience and cooperation.