Site work, paving and new construction of a bridge / tunnel in Miami, Florida. Conceptual plans call for the construction of a bridge / tunnel; for site work for a bridge / tunnel; and for paving for a bridge / tunnel.

Here's one idea to relieve downtown traffic: Dig a tunnel under the Miami River Six tunnel concepts developed by the Miami-Dade Transportation Planning Organization were recently examined at a Downtown Development Authority meeting. The group was opposed to designs that would cause dramatic trenching for huge entrance and exit ramps on Brickell Avenue, but supported tunnel alternatives that would maintain "pedestrian connections along key downtown corridors." In its feasibility study, the county recommended the option of two stacked bored tunnels with two upper northbound lanes and two lower southbound lanes to compensate for cramped space. Its north portals would be on Biscayne Boulevard, in the vicinity of Northeast Fourth and Second streets, where it would slope down beneath the foundation of the Metromover tracks, make its way southward, take a right turn at the river to continue under the bridge and avoid the Miami Circle, and emerge on Brickell Avenue with its south portals near Southeast 10th and 12th streets. The length of the tunnel, including portals, would be 2.1 miles, about the same as the PortMiami tunnel. "When we evaluated the pros and cons, that concept was the most feasible," said Jesus Guerra, deputy director of the transportation planning organization. "It provides a connection between Biscayne Boulevard and Brickell, avoids digging large ramps in the center of downtown, does not affect ships and cargo on the river and allows for placement of the boring machine." The cost would be $900 million and construction would take 4 to 4 1/2 years. The county's results were presented to the Florida Department of Transportation, which will conduct its own Traffic Analysis and Constructability Study. As of May 31, 2022, this project is in the conceptual phase. A consultant completed a feasibility study in 2017. The project is pending owner review. A firm timeline for construction has not been established. The method of contractor selection has not been determined at this time. *Project information, including timeline and contacts, has been obtained through public sources. The content management team continues to pursue additional details; however, the contact(s) listed have yet to disclose or confirm any information. Inquiries should be directed to the contact(s) listed.