Bear Cut Bridge replacement would cost $90 million

Construction to replace the aged and endangered Bear Cut Bridge linking Key Biscayne to Virginia Key and ultimately the mainland would cost Miami-Dade County $90 million and could be completed late in 2028, a report to county commissioners said this week.

The county has $5 million for the planning study phase of the project but no funds at all for designs or construction, the report says. The report does not suggest specific sources for the funding.

The report from Mayor Daniella Levine Cava was ordered Jan. 19, the day that commissioners officially ended a request for proposals issued after the county received an unsolicited plan from a group of firms identified as the Plan Z Consortium to develop, maintain and operate Rickenbacker Causeway, which would have included the consortium replacing the Bear Cut Bridge at its own cost.

The Venetian Causeway was initially included in the plan but was left out of the process in October. Cancellation of the request for proposals left the county to find a solution for the decaying Bear Cut Bridge, which leads to Crandon Boulevard, the only road serving Key Biscayne.

The bridge, constructed in 1944 during World War II, was widened from two lanes to four in 1983 with sidewalks and shoulders added.

Then in 2013, the Bear Cut Bridge went through major county rehabilitation, with a partial superstructure replacement and widening. But at that time, the county found in inspections that under-seabed pilings were also deteriorating. Because of the cost of checking, only eight of the about 400 pilings were inspected and two – 25% – were found to be below the required safety level. They were not replaced.

Those 2013 repairs were estimated to last for up to 20 years. If the bridge were replaced on the proposed schedule, a new Bear Cut Bridge would be available before the clock runs out on bridge durability.

In 2021, the county’s Department of Transportation and Public Works’ Highway Bridge Engineering Division began a periodic maintenance design project “to address common deficiencies of a bridge of this age,” the mayor’s report to commissioners said. “Deficiencies to be addressed include delamination, cracks and spalls at the columns, pier caps, piles and pile caps, seawall bulkhead cap and panels, slope protection and beams,” the report said.

The report recommended replacement “rather than continued major rehabilitation and repair of the bridge.”

The plan for replacement says the Department of Transportation and Public Works should advertise this month for professional services for a project development and environment study. That would be followed by advertisement and award of a planning, design and engineering contract in January 2023, to be completed in spring 2025.

If that schedule were met, the county could advertise for design-build services in spring 2025, then award the design-build contract in spring 2026.

Construction would be done for a total bridge replacement late in 2028, or in 2027 if the contract were just for major rehabilitation, the report says.

In order to replace the bridge, it states, “additional funding sources will be identified, and grant opportunities will be sought.”