Improving Nashville Commutes With Tennessee DOT’s Single-Largest Construction Project

Known as the "highway everyone loves to hate," Nashville’s Interstate 440 received its fair share of scorn for its congestion and potholes. But a landmark vote and first-of-its-kind team changed the sentiment for the 7.6-mile auxiliary loop south of downtown. 

Tennessee’s IMPROVE Act, passed into law in 2017, raised the gas and diesel taxes six cents and 10 cents per gallon, respectively. The funding gave way to significant transportation improvements, including a much-needed reconstruction of I-440. 

Built in 1987, I-440 originally saw 64,000 vehicles a day as a four-lane, divided parkway, and experienced a traffic increase to more than 100,000 vehicles a day. The east-west highway ran two lanes in each direction from I-24 to I-40 with major interchanges in-between. Mobility and safety concerns culminated 31 years later, and the Tennessee Department of Transportation embarked on widening I-440 — its single-largest construction project.
The reconstruction provided new asphalt paving, three lanes of travel in each direction with a median barrier, and improvements to entry and exit ramps and bridges throughout the corridor.

To take on a project of this scale, TDOT sought innovative delivery methods and procured an experienced design-build team, streamlining elements of design, regulatory permitting, utility relocation, and construction. The August 2018 contract award also represented TDOT’s largest design-build project. And to inspect construction activity, TDOT hired the HDR team.

To improve commutes, the new design called for a facility with at least six lanes. Construction, which took place during live traffic, included widening the I-440 bridges over I-65/Franklin Road/CSX railroad, Lealand Lane, and Craig Avenue; adding a median barrier; improving the intelligent transportation system; enhancing roadway lighting; mitigating rockfall; and repairing and installing noise walls.

To meet TDOT’s project goals, our CEI role included inspection of: traffic control, erosion control, grading, storm drainage, asphalt pavement, concrete pavement, drilled-shaft and steel-pile bridge foundations, bridge construction, retaining wall construction, median barrier construction, rockfall mitigation, noise wall construction, ITS, traffic signals, roadway lighting, and landscaping features. 

To expedite the widening project and make construction greener and safer, the design-build team rubblized the previous concrete. This saved the effort of tearing out the roadway, hauling in new base stone and starting from subgrade up. 

Bridge construction used extraordinary means as well. On the twin-span I-65 bridges, plans called for widening in the middle (i.e., between the bridges) to provide the extra lane width. The design-build team used dual gantry cranes to carry structural elements onto the bridge and then lower into place. Typically, teams would work from below the bridge or on the abutment, but these dual gantry cranes allowed traffic to continue, using a remote-control system to place girders and material and “walk” back off. To keep traffic live, the team placed concrete barriers to block off the shoulders from vehicles on each bridge, and the cranes extended to each shoulder and worked as cars passed.

The design-build team constructed I-440 on an aggressive schedule, including day and night shifts throughout the duration of the project. Advanced communication and documentation tools kept everybody aligned. 

Construction began November 2018, and the project completed July 2020. Much of the success can be attributed to the team’s focus and transparency.