Tuesday, July 14, 2020

Even ‘simple’ projects can have complications, so we prepare

Plan ahead for night closures on SR 99 Duwamish River Bridge in Seattle

By Tom Pearce

We have a saying around the office – there’s no such thing as a simple paver. On the surface a project to repave a section of highway may not look like a big deal, but sometimes things happen and that project quickly gets complicated.
Some of the existing steel deck grids have large patches where steel has broken.

On Sunday night, July 19, we’ll begin three weeks of weeknight closures, from 10 p.m. to 5 a.m., on the northbound State Route 99 Duwamish River Bridge, aka the First Avenue South bridge, in Seattle. Our contractor crews are going to replace some worn sections of the steel deck. When we started planning, this looked like a fairly standard preservation project. Then the West Seattle Bridge closed.

Uh oh.

Suddenly, the 100,000-plus vehicles that used the West Seattle Bridge each day had to find an alternate route. A lot of those trips moved onto the SR 99 Duwamish River Bridge, which already carries more than 50,000 trips a day.

See what I mean about no simple pavers (or bridge deck repairs)?
Travelers will have the choice of several other bridges
while the northbound SR 99 Duwamish River Bridge is closed.

Immediately after the West Seattle Bridge closure, we started looking at different options for getting into and out of Seattle besides the Duwamish River Bridge. We also worked with the Seattle Department of Transportation – which manages and maintains the West Seattle Bridge – to figure out alternatives and how to tell people about them. These alternatives include bridges in South Park, Tukwila International Boulevard, West Marginal Way and even Interstate 5.

Initially the Spokane Street lower bridge wasn’t on the table. That bridge is only one lane in each direction and is the main access point for businesses on Harbor Island – definitely not capable of handling more than 100,000 vehicles a day. And for the most part, it’s still not an option. However, things are different at night. There’s a lot less traffic – enough that SDOT is comfortable with letting all vehicles use the bridge during the overnight closures. So now we have that as an alternate as well.

People still need to limit their trips on the lower Spokane Street bridge, even at night. If you’re traveling after dark, you can help by using other alternate routes, depending on your starting and ending points. For example, if you’re at the south end of West Seattle, consider going east to Tukwila and take Tukwila International Boulevard or I-5. If you’re headed for Bellevue or points east and normally would use I-90, think about trying SR 518/I-405 to get there. The highway system provides plenty of options.

While there are no simple projects, there may be some relatively simple solutions to travel issues. We’ll do our best to plan for and provide ideas to help you get where you need to be.