DOTD, Atlas consultants present three alternatives for Mississippi River south crossing; NEPA expected to start in April 2025

Kara Morey, prime consultant for Atlas Technical Consultants, told the Capital Area Road and Bridge District on the project’s history and next steps, saying the project’s “ultimate objective is to construct a new crossing on the Mississippi River in the Greater Baton Rouge area.” Atlas described a two‑part contract: a completed enhanced planning study and an ongoing NEPA phase. The enhanced planning phase screened roughly 32 preliminary alternatives down to 10 and then three alternatives now carried into NEPA.

Atlas and Louisiana Department of Transportation and Development project manager Paul Vaught said the initial study area spanned about 62 river miles, from the Horace Wilkinson Bridge south past Donaldsonville, with LA‑1 on the west bank and LA‑30 on the east bank as corridor limits. The consultants said they used navigational constraints, environmental desktop data, stakeholder input (river pilots, levee districts, Corps districts) and cost parameters (including a noted threshold that main spans above ~2,000 feet dramatically increase costs) when eliminating options.

Consultants summarized public outreach and technical screening. Maria Bernard Reid, deputy project manager for Atlas, said the team held six public open‑house meetings in April–May 2022 with nearly 1,200 attendees and multiple comment channels; the transcript records that the team read and digested the comments and used public input as roughly one‑third of the screening decision with traffic and environmental factors. Atlas reported carrying three alternatives forward that are all located in Iberville Parish on the LA‑1 side and said the study will examine a roughly 600‑foot corridor (300 feet each side of the centerline) for each alternative as a worst‑case analysis while field studies proceed.

On traffic and usage, Atlas presented model results showing about 126,000 vehicles per day cross the I‑10 Horace Wilkinson Bridge (both directions) and that roughly 80% of traffic in the Greater Baton Rouge MPO is local rather than through traffic. The models estimate about 24,000 vehicles per day would use a new south crossing and that trucks make up roughly 15% of I‑10 bridge traffic. Paul Vaught added that the projected toll volumes used in the Toll and Revenue analysis account for diversions and that the lion’s share of the new bridge’s users would likely be drivers already using LA‑1.

Timing and NEPA scope: Atlas said pre‑NEPA work (flight, topo, subsurface utilities, bathymetric surveys) is complete, geotechnical borings and conceptual designs are underway, and the team plans to begin the NEPA clock in mid‑April. Reid stated Federal Highway Administration review of the planning material allowed the team to proceed with an Environmental Assessment (EA) and that an EA is typically a one‑year process from NEPA kickoff to a Finding of No Significant Impact (FONSI); she emphasized the project would convert to an Environmental Impact Statement (EIS) if field data indicate significant impacts. The consultants also pointed to a Planning and Environmental Linkage (PEL) product recognized by FHWA that will fold prior analyses into the NEPA phase and assist scheduling.

The district chair and DOTD said the next steps will include additional public and agency outreach during NEPA and, if needed, field delineations (wetlands/cultural resources) and mitigation planning. The consultants said they expect to identify a preferred alternative several months before a signed environmental document, which they anticipate by spring 2025.

What’s next: the NEPA phase will include more public meetings and agency coordination; Atlas and DOTD asked stakeholders and commissioners to continue to review posted documents at mrbsouth.com and to participate in the forthcoming NEPA public process.