Prepare for overnight bridge closures
January 5, 2010
State Department of Transportation crews will install electronic speed limit and lane-status signs above each lane on the Interstate 90 and state Route 520 bridges.Crews will intermittently close up to two lanes in both directions of I-90 between the floating bridge midspan and Bellevue Way nightly from 9 p.m. – 5 a.m. through Jan. 8.
The state DOT will close the onramp from Bellevue Way to westbound I-90 nightly from 9 p.m. – 5 a.m. through Jan. 7. Crews will close the high-occupancy vehicle onramp from Bellevue Way to westbound I-90 nightly from 9 p.m. – 5 a.m. through Jan. 7. Workers will also close the offramp from eastbound I-90 to Bellevue Way nightly from 9 p.m. – 5 a.m. through Jan. 8.
On Jan. 7, crews will close the westbound I-90 transit lane from Rainier Avenue to Airport Way from 9 p.m. – 5 a.m.
During the closures, state crews will drill shafts and place concrete for sign foundations.
Officials plan to install 25 signs along I-90, between Interstate 5 and 150th Avenue Southeast in Eastgate. The plan also calls for 19 signs on state Route 520 between I-5 and 130th Ave Northeast in Bellevue. The totals both include new signs mounted onto existing structures.
The new signs will post variable speed limits to warn drivers of backups ahead and smooth traffic as motorists approach a crash or other incident blocking a lane.
The overhead signs also can be used to quickly close entire lanes and provide warning information to drivers before they reach slower traffic.
Officials said the signs, known as active traffic management tools, have proved effective at reducing collisions and improving traffic flow in Europe.
State DOT figures show the technology resulted in a 30 percent reduction in collisions and a 22 percent increase in roadway capacity.
Officials said the signs should reduce congestion-related collisions and smooth traffic, cutting backups and stop-and-go traffic. Plans call for the signs to be constructed next month, with installation set for spring.
Officials plan to activate the state Route 520 signs in August, and the I-90 signs in March 2011.
The safety project is part of the Urban Partnership, a collaboration between the state DOT, King County and the Puget Sound Regional Council, a transportation planning organization.