The state plans next year to replace some of the worst-worn and most heavily traveled sections of three major interstates in the Puget Sound area. Some $280 million will be spent on projects for Interstates 5, 90 and 405.

In what likely will test the patience of Puget Sound commuters — think lane closures and detours — the state Department of Transportation plans next year to replace some of the worst-worn and most heavily traveled sections of three major interstates.

Some $280 million will be spent on the local road work, the most construction disruption in any year since the 1980s. Included on the list: Interstates 5, 90 and 405.

“We want to make sure drivers don’t hate us at the end of the construction season,” said Transportation Department spokeswoman Jamie Holter, and that is why, she explained, the state is releasing its closure list now. The state also is preparing videos on the closures to post on YouTube.

The work will close the express lanes on the I-90 bridges across Lake Washington for 40 days this summer. There will be I-5 lane closures from the Boeing Access Road in north Tukwila to Shoreline from February through September. There will be nighttime closures on I-405 from February through December. And the Olive Way offramp from I-5 in Seattle will shut down for as long as a year.

“This will be the worst year yet in terms of construction,” said Lorena Eng, Northwest Regional Administrator with the Transportation Department.

And the construction won’t end when 2009 is history, Eng said. There are still the state’s megaprojects: replacing the Alaskan Way Viaduct and the Highway 520 bridge.

In all, $279 million will be spent on road projects in King and Snohomish counties in 2009, up from $161 million this year. In King County alone, $147 million will be spent on roads, up from $72 million this year.

Next year’s road projects will proceed despite the state’s current budget woes. All are fully funded through the state gas tax. They should help stimulate the economy by providing needed jobs, Eng said. One project alone, on Highway 16 in Tacoma, will result in 200 new temporary jobs.

Eng said that because of the economy, bids are coming in lower than estimates. The I-5 paving project came in 37 percent under the estimate, the Transportation Department said. The estimate was $15.7 million; the bid came in at $9.9 million.

“This is the longest and most-challenging season ever,” said department spokesman Travis Phelps.

Susan Gilmore: 206-464-2054 or sgilmore@seattletimes.com