Construction crews who spent much of the summer repairing portions of road surface on Interstate 5 in Tacoma have moved to South King County, where theyre working on a notoriously bumpy section of freeway north of Federal Way.
With a budget of $6.7 million, workers are cutting out and replacing 64 deteriorated concrete panels and smoothing three miles of northbound I-5 between Military Road South and South 260th Street.
The work is taking place between 9 p.m. and 5 a.m. to minimize delays, said Broch Bender, a state Department of Transportation spokeswoman.
Nighttime lane closures began Oct. 22 and will continue through spring, when the project is scheduled to be completed, Bender said.
Crews are using the closures to replace cracked or broken 12-by-15-foot sections of concrete that form the driving surface. Theyll also use diamond-tipped blades to grind down the worn surface and remove ruts worn by tires, a process intended to extend the life of the concrete and provide a smoother ride.
The panel work is expected to be completed by December, the Transportation Department said. The grinding work will begin in mid-winter and continue through spring.
The project is financed by the state gas tax.
The project is in keeping with a policy of triage on I-5 in which repairs are undertaken on the worst of the worst sections, Transportation Department officials said.
The triage approach is not new to I-5. Two years ago, crews replaced 295 concrete panels on 25.5 miles of I-5 between Martin Way in Lacey and 48th Street in Tacoma.
This summer, crews replaced 75 damaged concrete panels on I-5 between 48th and M streets in Tacoma. In addition to replacing the concrete panels, crews ground more than five miles of freeway surface.
The interstate is made up of thousands of concrete panels joined by steel dowel bars. It takes 350 panels to make up one lane on a mile of freeway. A four-lane, mile-long section of I-5 contains 1,400 panels.
The steel bars linking the panels are flexible enough to bend slightly with the weight of traffic.
The pavement on I-5 through Pierce, King and Thurston counties is more than 50 years old, which Bender notes is more than twice its expected 20-year design life.
The freeway in this area predates the Space Needle, Bender said. The whole thing really needs to be replaced, but thats a $2 billion fix and theres no money for that now.
Between now and 2019, the Transportation Department has identified and the Legislature has funded nearly $130 million worth of concrete rehabilitation projects on state highways.
Rob Carson 253-597-8693