The Ted Williams Tunnel is the third crossing to be built under the Boston Harbor and was constructed as part of the Central Artery/Tunnel (CA/T) project, and carries I-90 from South Boston towards Route 1A. The 8,500-ft long tunnel includes a 4,000-ft long underwater section consisting of a twin steel immersed tube tunnel section. Tony Lancellotti, PE was responsible for the final design development and management of the project.