TDOT, consultants outline I‑40/I‑75 corridor study and options including choice lanes, relocation

Tennessee Department of Transportation officials and their consultants on Feb. 1 presented a planning and environmental update on the I‑40/I‑75 west‑Knoxville priority investment, describing a roughly 17‑mile study area, heavy truck volumes and a range of alternatives that will be narrowed through a Planning‑Environmental Linkages (PEL) study in 2025.

The project team said the effort is a PD&E (preliminary design and environmental) engagement meant to run engineering and environmental work in parallel so the department can move more quickly into project development and, eventually, construction on selected alternatives.

"This corridor is vastly important," Dexter Justice, TDOT’s point of accountability for the project, told the Knoxville Transportation Planning Organization. He said the corridor is part of a national freight network and that "truck volumes through here exceed 20%" of traffic. "Most interstates around the country see in the 5 to 10% range." Justice added that the study area covers about 17 miles from the I‑75/I‑40 interchange on the west side of Knoxville toward Lenoir City and north into Anderson County.

STV project manager Brad Thompson reviewed the study approach: inventory and mapping, a major environmental data collection program, 181 traffic count locations, origin‑destination analysis and development of a purpose‑and‑need statement. "We're going to be developing design options throughout the corridor," Thompson said, noting the team will score alternatives against constructability, cost and other criteria before forwarding a reduced set into a NEPA study.

Consultant Eric Zaggers of HNTB summarized "choice lanes," one of the study’s two bookend alternatives: additional lanes operated under a public‑private partnership and managed with tolling and ITS so the lanes maintain a reliable trip time. Zaggers said similar projects are being pursued by TDOT in the Nashville area. "They will be a user fee‑based system," he said, and the state would remain the underlying owner of the right of way while a concessionaire would operate and maintain the facility during the contract term.

Other alternatives the team listed include added general‑purpose lanes, collector–distributor roads, auxiliary lanes, interchange reconfigurations, weigh‑station relocations and a potential relocated alignment for I‑75 that would separate traffic currently combined on the same roadway as I‑40. The team is coordinating with Tennessee Highway Patrol, railroads, utilities and local jurisdictions to evaluate operational and right‑of‑way constraints.

The presenters cited local traffic patterns and bottlenecks: the corridor includes multiple top‑ranked statewide bottlenecks, and the team reported peak daily volumes at about 200,000 vehicles on portions of the 17‑mile study segment, with lower counts (about 45,000–50,000 ADT) north and south outside the core. The consultants said safety issues — a cluster of crashes around interchanges such as Watt Road and Campbell Station Road — contribute to delay and will be a factor in evaluating alternatives.

Timeline and next steps: the presentation said the team expects a draft PEL report in 2025 and a public outreach program with two public meetings (an April meeting and a follow‑up later in the year) to present alternatives and collect comment. The PEL will produce a range of alternatives, preliminary cost estimates, a recommended phasing and potential funding strategies to guide the subsequent NEPA and preliminary design phases.

Questions from TPO members focused on travel demand and the origin‑destination work that will determine how much traffic could be diverted by a relocated I‑75, the role of weigh stations and truck operations in creating weaving movements, and the potential for federal funding. Justice said the study will use origin‑destination data to estimate diversion and that "it's not necessarily a guarantee that if you were to relocate it all that traffic will be diverted." Mayor Ron Williams asked whether federal funding was a feasible path; Justice replied, "every avenue is on the table today."

The presentation named the consultant team (STV prime; with Stantec, CDM Smith, Cannon, Robert Campbell and Parsons) and described an expedited schedule and an elevated level of front‑loaded engineering and environmental analysis. The presenters emphasized that public input will inform purpose and need, alternatives and decisions going forward.

The team did not present a final decision at the meeting; the session was an informational briefing and the PEL process will produce the formal alternatives and recommended next steps for TDOT and stakeholders.