Friday, September 2, 2011

Building a freeway ramp, one truckload at a time

By guest blogger Mike Murphy

What does it take to rebuild an entire freeway ramp, move it about 100 yards and raise it about 20 feet?

A lot of workers and a lot of dirt.

Late last week we opened a new ramp connecting Weyerhaeuser Way and westbound SR 18 to northbound I-5 in Federal Way (nearly a week early, by the way). And it was no small task.

Our contractor crews closed the ramp on Aug. 8 to begin demolition. They needed to get the ramp out of the way to make room for a new “flyover” ramp that will eventually take cars and trucks from westbound SR 18 directly to southbound I-5. (Right now you take what we call a “loop ramp” which leads to weaving across many lanes of traffic.)

WSDOT Inspector Sam Al-Mallah oversaw the whole operation to make sure everything went smoothly.
“The subcontractor had nearly 30 different pieces of earth-moving equipment working 20 hours per day,” he said. “Our crews were on-site around the clock to spot any issues as they surfaced and avoid possible delays.”

Al-Mallah has been with WSDOT for 20 years and this is one of the biggest projects he’s worked on yet.

“We had to move close to 42,000 cubic yards of dirt for the new, higher ramp. That’s about 1,900 large truckloads,” he said. “Luckily, the dirt was removed from other parts of the project, so we didn’t have to haul in any new material. That’s what we call a balanced project.”

 If you drive this area, you’re definitely going to notice some changes. Drivers headed on westbound SR 18 will enter the northbound I-5 ramp further east. They’ll share the ramp with traffic coming from Weyerhaeuser Way.

This long-awaited project will completely transform how traffic merges between the busy I-5/SR 18/SR 161 interchange. Two new flyover ramps, including the one mentioned above, will eliminate lane weaving that can lead to congestion and collisions. It’s even more beneficial when you consider that roughly 7,200 semi trucks use SR 18 in this area every day.

So what’s next? Later this fall, we’ll begin installing huge steel beams (called bridge girders) over I-5 for each of the new flyover ramps. That work will require a few overnight total closures of I-5 in Federal Way.

Check the project website for more specific information as the work gets closer.