From King County:

The King County Road Service Division will close the South Park Bridge spanning the Duwamish River to both vehicle and marine traffic from 7 a.m. – 7 p.m. daily Saturday Jan. 30 through Tuesday, Feb. 2. The four-day closure will allow engineers to perform noise and water quality testing and simulate vibration that might occur during bridge construction. During the closure, engineers will conduct pile driving to measure noise, vibration and take water quality samples. Data collected during the tests will assist the county in planning for construction of a new bridge when financing becomes available. During the closure, motorists can detour via the First Avenue South Bridge.