Caution: Sticky 1-90 traffic ahead

Representatives from WSDOT enlightened Mercer Island Chamber of Commerce members about the forthcoming I-90 closures and their effect on traffic flow at the Chamber’s luncheon on March 5.

Center roadway closures in May

Representatives from WSDOT enlightened Mercer Island Chamber of Commerce members about the forthcoming I-90 closures and their effect on traffic flow at the Chamber’s luncheon on March 5.

According to the WSDOT representative, Islanders should expect at least 45 minutes of delay when commuting across the I-90 bridge during the first phase of joint-repair construction, May 4-23, when the center roadway will be closed. All westbound traffic will use the mainlines, as the center express lanes will be closed.

During the project’s second phase, July 5-28, all westbound traffic will use the center roadway while the mainlines are closed for construction. This means that Island commuters heading to Seattle must get onto the freeway at Island Crest Way or 77th Avenue S.E. All eastbound I-90 on- and off-ramps will be open throughout construction. Again, WSDOT predicts a traffic delay of 45 minutes across the bridge.

The flow of Island traffic onto I-90 will also cause congestion in the Town Center. Traffic officials will set up detour signs if backup becomes a significant problem near the I-90 on-ramp. Police officers will also serve as traffic controllers during this time.

WSDOT encourages Islanders to carpool to work, take the Metro or even bike to Seattle if possible during the two phases of work.

Bike access across the bridge will be open 24/7 with the exception of an eight-hour period in July. In order to assist cyclists and pedestrians, WSDOT will construct two temporary bridges for the July project, one at each end of the floating bridge. Cyclists must dismount and walk across the temporary bridges.

Another option, the WSDOT representative said, is to take vacation during the weeks of construction. Otherwise, commuters should be prepared for the delayed traffic.

The Reporter will update news on the May and July projects over the coming months. More information is available at: www.wsdot.wa.gov/Projects/I90.

I-90 seismic upgrades begin

WSDOT crews have begun work to strengthen the columns, girders and crossbeams of the double-decked overpass that carries I-90 over I-5 to better withstand earthquakes. Crews will also strengthen the supports of the nearby 12th Avenue S. Bridge, starting in May.

Crews will work mostly at night to keep traffic moving during the day. Drivers should expect overnight lane and ramp closures through June 2010 at the I-90/I-5 interchange. Drivers can keep up-to-date on the latest closure information at www.wsdot.wa.gov/Northwest/King/Construction. For more information about the project, visit www.wsdot.wa.gov/projects/i90/i5to12thseismic.

WSDOT built major portions of the double-decked I-90 overpass in the mid-1960s, but they stood unused for more than 20 years because of legal challenges and became known as part of the “ramps to nowhere.” In 1988, WSDOT connected the overpass and ramps at the interchange to I-5 and I-90.

The project is part of WSDOT’s seismic retrofit program. WSDOT is strengthening more than 900 bridges and structures across the state to better withstand earthquakes. WSDOT built these bridges and structures before stricter seismic standards were established.