The Alaskan Way Viaduct Replacement Program is led by the Washington State Department of Transportation in partnership with the Federal Highway Administration. Built in the 1950s, the SR 99 viaduct, a 1.4-mile double-deck concrete structure, was seismically vulnerable. The removal of the viaduct was a challenging project due to the density and proximity of residences and businesses. The project included 12 months of nighttime construction and up to five crews working at one time. S&A was hired by the design-builder, Kiewit, to conduct construction communications to frontline businesses, residents, and property owners, as well as the traveling public.