$9M rehab could mean long-term closure for Tacoma Ave South Bridge

A $9 million rehabilitation project scheduled to begin later this year could close the Tacoma Avenue South Bridge for 12 months, according to City of Tacoma officials.

The 80-year-old bridge’s beams, sidewalks, guard rails and deck have deteriorated so severely, according to city staff, that lanes have been closed and weight restrictions have been implemented. The bridge is a vital link between downtown Tacoma, the Lincoln International Business District and beyond.

Two years ago, the city was awarded a $7.2 million federal grant to help pay for the project. The city is contributing approximately $1.8 million toward the project. In August, the city awarded a $1.2 million contract to Bellevue, Wash.-based TranTech Engineering to complete the bridge design.

Tacoma City Council’s environment and public works committee is scheduled to meet Wednesday to discuss staff recommendations for moving forward on the project.

A key recommendation calls for completely closing the bridge to vehicles, instead of implementing phased closures, during construction.

“Staff is also recommending full closure of the bridge during the construction phase of this project,” wrote Tacoma Public Works Director Dick McKinley in a Jan. 23 memo. ”Phased closure would cost $1 million in construction funds that is included in the $9 million budget and require an additional six months to construct. Full closure will have the largest impact to the surrounding community. To mitigate this impact, we are working on a detour route that will promote the use of Delin Street / South G Street. We are also working on a plan to maintain a pedestrian / bicycle path across the bridge during construction.”

Another recommendation calls for installing a concrete guard rail instead of a steel guard rail. “Staff has received strong support via e-mail from the community . . . focused on the visual aspect of a concrete guard rail and how it provides a historic connection with the bridge,” added McKinley. “The steel guard rail would cost approximately 10 percent less than the concrete rail and would result in a savings of about $20,000. This is a small savings when compared with the total project cost of $9 million. The concrete guard rail does impart a larger seismic load to the bridge during an earthquake. The increased seismic force due to the concrete guardrail does not require additional work. Both designs are within the parameters of standard bridge construction.”

City staff also recommend the final bridge deck configuration include two lanes for vehicles, a center turn lane, two lanes for bicyclists and two sidewalks for pedestrians.

The bridge design is approximately 20 percent complete. Construction is expected to begin this fall and last approximately one year.

Tacoma City Council’s environment and public works committee is scheduled to discuss the staff recommendations for the bridge during a public meeting on Weds., Jan. 23 at 3 p.m. at Tacoma Municipal Building North, located at 733 Market Street, Conference Room 16. More information is available online here.