Finalized Sept. 18, the $2.52-billion Transportation Infrastructure Finance and Innovation Act (TIFIA) loan provides the final funding component for the $3.2-billion first phase, anchored by a new 2.5-mile-long cable-stayed bridge spanning the Mobile River navigational channel. The bridge will eliminate a longstanding bottleneck by bypassing a pair of tunnels built in the early 1970s. ALDOT previously received $675 million from two federal grant programs for the project.

KMT has been preparing for the expected five-year construction phase since being selected for the project in 2023. Along with improving travel times along I-10 and access to the Port of Mobile, the six-lane tolled structure will provide a more efficient Mobile River crossing for hazardous freight vehicles that currently must detour through neighborhood streets.

After more than 30 years of planning, the Bridge and Bayway project has faced a challenging road to reality. ALDOT's original plan called for building the main bridge alongside the replacement of more than seven miles of existing concrete viaducts across Mobile Bay, known as the Bayway, with wider structures elevated 14 ft above the 100-year storm-surge level.

Amid public resistance to a proposed toll structure, ALDOT scuttled its plan to carry out the project as a public-private partnership in 2019. Delays and costs continued to mount, however, with an ALDOT fact sheet citing unexpected geotechnical and engineering challenges on the Bayway as compounding rising labor and material costs.

Already the largest infrastructure project in state history, the program was nearing the point of becoming financially unviable, ALDOT said. The agency said adding right-of-way acquisition, utility relocation, contingencies, capitalized interest and toll-system integration pushed the total Phase 1 cost estimate above $4.1 billion, compared with the $3.2-billion design-build construction contract value.

ALDOT has not released a revised cost estimate for the Bayway improvements. Harris said the agency "will continually seek additional funding opportunities with a goal of beginning construction for replacement of the existing Bayway in 2036." As an interim capacity-improvement measure, KMT's Phase 1 work includes reconstructing about a mile of the Bayway and restriping the existing viaducts to provide three lanes in each direction.

Tolling will not begin until the bridge opens, currently projected for late 2031. Under a toll policy adopted Sept. 8 by the Alabama Toll Road, Bridge and Tunnel Authority, rates will be higher than the $2.50 per-trip and $40 monthly rates local officials endorsed in 2022 and will no longer remain flat. Tolls will increase annually by 5% or the regional inflation rate, whichever is higher, during the first 10 years. Subsequent increases will be the greater of 2.5% or the rate of inflation.