FDOT evaluated a proposal to put a portion of I-395 and Biscayne Boulevard underground, instead of building a Signature Bridge. The results:

The tunnels would cost $1.3 billion more than the Signature Bridge

Both Biscayne Boulevard and I-395 would have to be locked down during Hurricane events due to flooding concerns, closing vital evacuation routes

Metromover would need to be reconstructed, with associated cost and service disruption

Biscayne Boulevard and other nearby streets would need to be closed during construction

Pedestrian crosswalks would be eliminated in some areas near the tunnel. Nearby streets would also need to be elevated, inhibiting access

Likelihood of contaminated soil during excavation. Area was previously occupied by the Belcher Oil Terminal & Tank Farm

Construction would be delayed an extra five years for a Supplemental Environmental Impact Statement

FDOT’s Gus Pego will present the study, along with an update on the Signature Bridge, to Miami commissioners next week.