Phase two of the Bronson Way Bridge seismic retrofit and painting begins this week, causing a road closure and detours that could take up to two months.

There will be a full closure of Bronson Way South between North Riverside Drive and Mill Avenue South starting Monday, May 15 as workers give the bridge its first seismic retrofitting, along with bridge preservation and more painting.

The Renton City Council authorized the closure for up to 60 calendar days, which would be Friday, July 14.

The City of Renton has designated alternate routes for both vehicles, pedestrians and those taking the Cedar River Trail.

Northbound traffic on Main Avenue South and South 3rd Street will be re-routed to Houser Way South. Southbound traffic will be re-routed to Sunset Boulevard North, which will take a left onto Factory Place North, another left onto North 4th Street, a left onto Logan Avenue North going over the bridge and then turning onto Logan Avenue South to South 2nd Street.

Pedestrians wanting to cross the bridge have two options: taking North Riverside Drive and then turning left onto Wells Ave and then left onto South Riverside Drive or walking southeast onto the Ceder River trail and then walking across the small walking bridge behind the Renton Library, continuing onto Mill Avenue South.

The Cedar River Trail detour will be similar to the pedestrian detour except trail users will not be able to use North Riverside Drive and are instead encouraged to walk across the small walking bridge behind the Renton Library, continue onto South 2nd Street and then take a right onto Bronson Way South before turning left onto South Riverside Drive and then taking a right onto the Wells Avenue South bridge, where the Cedar River Trail will continue to the Northwest. For trail users walking southeast, the directions are in reverse.

The anticipated seismic retrofit for the steel main span of the bridge includes temporary elevation using hydraulic jacks, removing the existing rocker and fixed bearing and also installing new elastomeric bearing pads on new concrete bearing pedestals.

Construction work will also include maintenance on the bridge deck, where workers will remove the existing asphalt overlay wearing course, repair the underlying concrete deck, remove existing steel slide plate expansion joints, repair existing concrete curbs, adjust the bridge drain inlet grates, install new compression seal expansion joints, new waterproofing membrane on the concrete deck and new asphalt overlay wearing course on the concrete deck.

Built in 1939, the Bronson Way bridge has never had a seismic retrofit, which would make the bridge resistant to earthquakes, soil failure and other ground motion.

Phase one of the bridge project began on Sept. 23, 2003, and was completed on Oct. 14, three weeks ahead of schedule. Construction is estimated at $2.5 million and is contracted by Combined Construction, Inc.

Updates on the project can be found on the City of Renton website where residents are able to sign up for an e-newsletter on the project. Emails can be directed to bronsonbridgeconst@stephersonassociates.com and a construction hotline can be reached at 425-224-2449.

Pedestrians are encouraged to use this detour map during the bridge closure.