Interstate 405 has seen its share of congestion relief work in recent years, including two projects now under construction in Bellevue.

On Tuesday, officials with the state Department of Transportation briefed Bellevue City Council members on progress and previewe of what lies ahead.

In the past five years, the Legislature has authorized more than $6 billion in state gas tax and other revenue for dozens of congestion relief projects statewide. Of that, $1.51 billion has been budgeted for projects along the 30-mile length of I-405. So far, one project in Kirkland has been completed, four are under way and three others are scheduled to break ground in the next two years.

In Bellevue, the biggest impact will be felt in August when the Department of Transportation closes all southbound lanes of I-405 on three consecutive weekends to remove the Wilburton Tunnel.

State transportation officials provided updates on three projects in Bellevue:

I-405 South Bellevue Widening Project: Designed to relieve congestion in one of the area’s worst sticking points, in and out of downtown Bellevue, the $197.2 million project will add one southbound lane from Southeast Eighth Street to Interstate 90 and one northbound lane from 112th Avenue Southeast to Southeast Eighth Street. Work started in spring 2007 and is scheduled for completion in late 2009.

To make room for more southbound lanes, crews will remove the Wilburton Tunnel and southbound I-405 will be closed from Southeast Eighth Street to I-90, from 11 p.m. Friday to 5 a.m. Monday on the weekends of Aug. 8 to 11, Aug. 15 to 18 and Aug. 22 to 25. The northbound lanes will remain open. Workers will use six large excavators, described as “crunchers and breakers,” and a crane with a wrecking ball to do the job.

The suggested detour will route southbound I-405 traffic to westbound SR 520, southbound I-5, eastbound I-90 and back to southbound I-405. A local, “open for business detour,” will be available for traffic out of downtown Bellevue, but delays are expected.

I-405, Northeast 10th Street Bridge: The Department of Transportation and city of Bellevue are working together to extend Northeast 10th Street from 112th Avenue Northeast east over I-405 to 116th Avenue Northeast. It’s designed to provide better access between downtown Bellevue, west of I-405, and the city’s growing hospital district east of the highway. It also relieves congestion on busy Northeast Eighth Street.

Stage 1 of the project, building a section of road from 116th Avenue Northeast to I-405, was completed in mid-May. Work on Stage 2, to finish the connection over I-405, is expected to be complete in fall 2009. Landscaping and a storm water pond west of I-405 are also part of the $63.7 million total cost.

I-405, Northeast Eighth Street to SR 520 Braided Ramps: Still in the planning phase is a $255 million project intended to eliminate the “weave” between drivers heading north on I-405 out of downtown and those on I-405 who are exiting to SR 520. The work, scheduled to begin in 2009 and wrap up in 2011, will include stacked lanes to separate traffic, a new on-ramp at Northeast 10th Street to SR 520 and a new overpass at Northeast 12th Street.

For more information on Department of Transportation projects in Bellevue and elsewhere on I-405, visit the website at www.wsdot.wa.gov/Projects/i405/.