The final phase of the I-20/59 bridge replacement project in Birmingham, Ala., will be rebid after the first round of bids exceeded state estimates.

Replacing the 40-year old, 1.25-mile elevated structures through Birmingham’s central business district and associated road work has long been considered the most complicated element of the three-phase, $750-million program, which began in 2015.

But the three bids received were “significantly” above the agency’s estimated range of $292 million to $357 million, according to state Transportation Director John Cooper.

Rebidding the project may have a silver lining for ALDOT. Cooper says contractors will be asked to augment their bids with alternative construction methodologies and sequencing strategies that could help expedite the project’s completion, and limit the amount of time that through traffic is diverted onto other highways. Currently, the I-59/20 bridges handle approximately 160,000 vehicles daily, double their original design capacity.

Cooper notes that because ALDOT has a base design in place for Phase 3, the rebid project is not a “full-blown” design-build project. However, last year’s legislative authorization for ALDOT to begin using design-build, “allows us to seek alternative technical concepts,” he adds.

ALDOT had previously announced that the contract for Phase 3 would include financial incentives for early completion.

The agency has set a March 31 deadline for the new bids, and plans to select a contractor by early April. Bridge replacement work could begin as early as mid-2018.