Crews opened the first half of the new N.E. 12th Street Bridge to traffic early Tuesday morning, marking a construction milestone that will allow them to tear down the old bridge the first weekend in April.

The bridge removal and replacement is part of the larger Bellevue Braids project to better connect Bellevue, Interstate 405 and State Route 520. The work will require a temporary full closure of I-405 and drivers should plan ahead for delays.

“We’re building the new N.E. 12th Street Bridge in stages to keep traffic flowing smoothly in Bellevue during construction,” said Seema Javeri, WSDOT Project Engineer for the I-405/SR 520 Bellevue Braids Project. Crews will build the second half of the new bridge after tearing down the old bridge.

Last August, cranes lifted eight 100-ton concrete girders over the freeway to form the skeleton of the southern part of the new N.E. 12th Street Bridge. After seven months of work drivers are using the first piece of the new structure.

When finished in the summer of 2012, the new bridge will be higher, wider and longer than the old bridge to make way for new northbound ramps headed to SR 520 and I-405. The $107.5 million Bellevue Braids project is funded by a combination of federal American Recovery and Reinvestment Act funding and the 2005 gas tax. The new N.E. 12th Street Bridge will feature a pedestrian and bicycle lane separated from traffic.

To remove the old bridge and ensure the safety of drivers, crews plan to completely close I-405 in both directions between N.E. Eighth Street and SR 520 in Bellevue for 53 hours the first weekend in April. The full closure will begin at 11 p.m., Friday, April 1 and the highway will reopen to traffic by 4 a.m., Monday, April 4.