The PortMiami Tunnel is a 4,200-foot, undersea tunnel in Miami, Florida. The PortMiami Tunnel was designed to address the economic problems and safety concerns that existing truck and bus routes created. The PortMiami Tunnel consists of two parallel tunnels that run beneath the Biscayne Bay and connect the MacArthur Causeway on Watson Island with PortMiami on Dodge Island. The project also included roadway work on Dodge and Watson Islands, widening of MacArthur Causeway Bridge, and a specifically constructed 43-foot diameter tunnel boring machine. Design and construction costs totaled $667 million.
The PortMiami Tunnel Project is a public-private partnership between the Florida Department of Transportation, Miami-Dade County, the City of Miami, and MAT Concessionaire, LLC (MAT). MAT, a private entity, was in charge of designing, building, and financing the project. MAT hired Bouygues Civil Works Florida as the general contractor.
Construction began in May 2010 and was complete by August 2014. Because of the PortMiami Tunnel, PortMiami remains a competitive economic generator and downtown streets are less congested, therefore safer. Within the first month of operation, the tunnel averaged 7,000 vehicles per day.