The Port of Miami Tunnel has improved access to and from the Port of Miami, serving as a dedicated roadway connector linking the Port (located on an island in Biscayne Bay) with the MacArthur Causeway (State Road A1A - which connects Miami to Miami Beach) and I-395 on the mainland.  Currently the Port is linked to the mainland only by the Port Bridge.  The project includes a tunnel under the Main Channel, roadway work on Dodge Island and Watson Island/MacArthur Causeway, and widening the MacArthur Causeway Bridge.

The project was developed as a public-private partnership (P3) with Miami Access Tunnel, LLC (MAT).  The State has agreed to pay for approximately 50 percent of the capital costs (design and construction) and all operations and maintenance, while the remaining 50 percent of the capital costs will be provided by the local governments. 

The tunnel has improved access to the Port by rerouting many cargo trucks, buses, cruise suppliers, cruise passengers, and taxis away from the streets of downtown Miami.  In doing so, the tunnel has eliminated leading causes of congestion, improving road safety in downtown Miami and according to the Project Sponsor saves an estimated 3,400 total vehicle hours per day.  The tunnel creates further value for trucking companies by reducing the duration of a drayage truck’s round-trip to port by approximately 40 minutes each way, potentially allowing drivers to make additional revenue-bearing trips during their regulated day.  The project is expected to create over 33,000 and generate approximately $2.25 billion in total economic impact, and it will continue to facilitate ongoing and future development plans in and around downtown Miami. TIFIA financing allows for the realization of these benefits at financing cost savings of approximately $370 million.