Project at a Glance

• Location: Dyer County, Marshall County, Giles County, and Roane County

• Client: Tennessee Department of Transportation (TDOT)

• Purpose: Give TDOT's Traffic Management Center real-time visibility and driver communication on rural interstates.

• Scope: CCTV cameras, radar detection, environmental sensors, connected vehicle roadside units, dynamic message signs, wireless communications, and 3,000 feet of dual bridge-mounted conduit

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About the Project

TDOT’s SmartWay system gives the Traffic Management Center eyes on Tennessee’s interstates, but many rural stretches have never had that coverage. CNZ273 extends SmartWay to sections of I-155, I-65, and I-40 where the TMC previously had no visibility.

 

Cameras and radar detection let operators watch traffic and spot incidents as they happen. Environmental sensors report road conditions, and roadside units prepare the interstate for connected vehicles. Dynamic message signs warn drivers about crashes, closures, and weather ahead. Every site connects wirelessly back to the TMC, so incidents get a faster response and drivers get better information. The project covers four counties from the Missouri state line to East Tennessee, which makes it five separate job sites, each with its own scope.

 

Challenges

Schedule pressure started before construction did. During preconstruction planning, suppliers reported that lead times for several key materials had grown well beyond what was expected at bid. With demand from data center construction tightening the supply of conduit, the team had to make every week count.

 

The most demanding work on the project is on the I-155 bridge that connects Tennessee and Missouri. Crews are installing 3,000 feet of dual 2" and 4" fiberglass conduit along the bridge, which required large cores through the bridge webbing and hundreds of holes drilled into the decking to mount the hangers. A plan revision partway through added another hurdle on top of the material delays.

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Solutions

During the submittal process for the environmental sensor station, the team found that the planned pole location would not work with the sensor’s mounting requirements. Catching it at that stage, before the foundation was poured, avoided a costly fix later.

 

Working closely with TDOT, the team got approval to relocate the CCTV pole, secured re-engineered plans, and installed new guardrail, all before the required drill date and with no schedule slip. Clear communication on both sides turned a potential setback into a quick resolution.

 

To save time in the field, Stansell Electric's Virtual Construction and Fabrication (VCF) team modeled and fabricated the foundation cages along with the demarcation and standard power service racks. Building them in the shop saved field crews about a week of work on a tight schedule. Several of them had not built DMS cages or service racks to these requirements before, so the project also expanded their skills.
 

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Key Features

• SmartWay coverage extended to rural stretches of I-155, I-65, and I-40

• 3,000 feet of dual 2" and 4" fiberglass conduit installed on the Tennessee-Missouri bridge

• Wireless communications linking every site back to TDOT’s Traffic Management Center

• Connected vehicle roadside units preparing the corridor for future technology

• VCF-fabricated foundation cages and power service racks

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Outcome

CNZ273 brings real-time monitoring and driver communication to rural interstates that TDOT couldn’t see before. Stansell’s Nashville and Knoxville teams have worked together across five sites and more than 400 miles of interstate, meeting TDOT’s detailed requirements on everything from grounding materials to phase sequencing. During site visits, TDOT representatives noted the crew’s consistent focus on safety and the quality, professionalism, and coordination behind each installation.​​

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