April 17, 2009 · Updated 8:27 AM
Traffic nightmares are likely this spring and summer as WSDOT tackles a long to-do list with local highways.
Next up is the I-90 floating bridge, where the center roadway be closed for nearly three weeks as workers replace cracking expansion joints on the 20-year-old structure from May 4-23.
WSDOT is telling drivers to expect delays westbound in the morning and eastbound in the evening, with traffic times possibly doubling between 6-11 a.m.
The westbound mainline will then close from July 5-28 to swap out the joints for that portion of the bridge.
WSDOT estimates that the commute between Bellevue and Seattle will at least triple during that time, with the rush-hour drive taking nearly 50 minutes.
Traffic congestion is expected to increase throughout King County as a result of the joint-expansion work, as well as other highway projects that are taking place in the region.
"This is a very complicated and intense construction season," said WSDOT spokesman Travis Phelps. "It's very long, and it boils down to the fact that a lot of our infrastructure is aging."
WSDOT is advising commuters to avoid driving or share rides as the projects move forward.
"We need drivers to really be thinking ahead about other ways they can get to work or work from home," Phelps said.
WSDOT has offered the following incentives for people to share rides:
The first 3,000 commuters who join or start a carpool on RideshareOnline.com will get a $20 gift card.
Commuters who sign up for a new King County Metro vanpool with at least four people by July 1 will receive three free months.
Busses apparently won't be a solution, since they're already filled to capacity.
"If you're a new transit rider, don't count on there being space available," said WSDOT spokesman Mike Murphy.
The bridge work on I-90 has an estimated cost of $8.3 million.
The project will replace two sets of expansion joints that have been cracking since the bridge first opened. WSDOT has been battling the fractures with welding.
"It's at the point where we're putting welds on top of welds now," Murphy said.
A fully cracked expansion joint would ultimately force a bridge-closure for up to six months because a custom-made replacement piece would have to be made.
Drivers would also be at risk.
"When these joints pop up into traffic, your car can hit it at a significant speed," Phelps said. "Is it going to pop up tomorrow? No. It's not a safety issue today, but it could be in the very short future. That's why we're doing this work right now."
WSDOT maintenance crews inspect the bridges on a weekly basis, according to WSDOT engineer Ralph Dornsife. None of the joints have ever fractured completely, he said.
Approximately 71,000 vehicles use the I-90 floating bridge every day, according to WSDOT.
The structure's new expansion joints are designed to resist fatigue and expected to last until the end of the bridge's projected lifespan 50 years from now, Dornsife said.
The new joints will also be made of solid steel, whereas the originals consist of tube steel.