Many Southern Middle Tennessee drivers have already traveled through the work zone at Exit 46 on Interstate 65 (I-65) in Maury County. The construction will last approximately three years, but the process started nearly two decades ago. The Tennessee Department of Transportation (TDOT) contracted with Sain Associates in 2002 to begin planning for modification of the interchange.
Sain Associates received a work order to prepare an Interchange Modification Study for the Interchange of I-65 and State Route 99 (SR-99)/U.S. 412, also called Bear Creek Pike. The focus of the study was operational concerns on the ramps and safety concerns regarding the sight distance at the ramp terminal intersections. We completed the study in 2003, and it was approved by the Federal Highway Administration (FHWA) in the same year.
In 2012, we received a work order from TDOT to update the previous study for current conditions and to conform to new FHWA standards for an Interstate Access Request (IAR). The study identified several environmental constraints, including the Jones Cemetery in the northeast quadrant of the interchange. Existing and future commercial development around the interchange and growth in Maury County were factors in the study and recommendations. The final report recommended replacing the bridges, widening SR-99, installing traffic signals at the ramp termini, and improving the ramps. Ramp improvements included removing the loop ramp and constructing a new northbound entrance ramp that required retaining walls to avoid impacting the cemetery. The FHWA approved the report in 2015.
TDOT then began the design process using their in-house engineers. The design faced several unique challenges, such as the retaining walls, the bridges, and the existing underground utilities. The design was completed in 2020, and the project was let to contract in May 2021 with Eutaw Construction Company, Inc. receiving the contract. Per TDOT’s Pre-Bid Meeting, the construction challenges include:
- Constructing three retaining walls with a gas line nearby
- Raising the grade of I-65 and lowering SR-99 to maintain bridge clearances
- Relocating a stream
- Demolishing both bridges and replacing them with one bridge
The finished product will be a standard diamond interchange with one bridge with a completion date of June 30, 2024. I look forward to watching the construction of a major project close to home and that I had a part of, but even more, I look forward to seeing the completed interchange that is functional and safe for drivers.