TDOT outlines package of alternatives for I-40/I-75 corridor; public open houses set next week

Amanda Snowden, regional director for East Tennessee for the Tennessee Department of Transportation, told the TPO Executive Board the West Knoxville Corridor PEL study is intended to link planning work and environmental review to speed later NEPA actions. "A PEL is planning and environmental linkage study," Snowden said, adding the study allows alternatives and public input to be considered early.

Consultant Brad Thompson (STV) said the study covers a 17‑mile mainline of I‑40/I‑75 with a larger study area to test options including a possible I‑75 bypass. He said the project team has completed the framework and purpose‑and‑need work and is screening alternatives ahead of an alternative evaluation report and a final PEL this fall. "If you don't do anything to the corridor it's going to be much worse than it is today," Thompson said, summarizing congestion trends shown in the team's analysis.

The team presented a range of alternatives under evaluation: adding a general‑purpose lane in each direction to widen the interstate; collector–distributor roads to separate ramp weaving; barrier‑separated choice/managed lanes that could use dynamic pricing; a 25‑mile I‑75 bypass (four lanes, 70‑mph design) to divert regional truck traffic; technology and TSMO measures (ramp metering, variable speed limits, dynamic messaging and connected‑vehicle tech); a targeted, lower‑cost package of spot improvements (ramp/interchange fixes and selected capacity additions); and express bus service leveraging park‑and‑ride sites.

Thompson described tradeoffs: widening and managed‑lane options add capacity but carry significant right‑of‑way, environmental and construction impacts; the bypass would create major new community and environmental impacts and would not modernize the existing mainline; and TSMO or express bus elements are most effective when paired with corridor improvements. He said funding is the major constraint across options and that the PEL will feed a NEPA phase where detailed environmental and air‑quality analyses will be completed.

Board members asked whether a PEL replaces NEPA. Thompson and project staff said it does not; rather, the PEL is designed to shorten the NEPA phase by advancing planning and environmental considerations now. "We still do have to go through a NEPA process. It's just the idea is that the NEPA process would be shortened because of the results of this study," Thompson said.

TDOT staff and board members also discussed shorter‑term modernization and traffic‑signal coordination on state routes inside the city (Kingston Pike, Middlebrook Pike, Northshore) and the potential role of express bus service when paired with priority lanes. Kristen Walls (TDOT) said express buses could use choice lanes without user fees and provide reliable transit movement when integrated with managed‑lane options.

The project team emphasized the PEL is a screening and decision‑support exercise: alternatives go through a fatal‑flaw screen, then detailed evaluation using costs, travel‑time benefits and environmental grading to produce a recommended portfolio. The team invited public comment and noted three open‑house meetings next week (Monday–Wednesday, 5–7 p.m., open‑house format) to display alternatives and receive feedback. Thompson said the team aims to complete the study by fall.

The meeting closed the PEL discussion and moved on to other agenda items.