On April 1, 1989, the Hatchie Bridge in Tipton County, Tennessee, collapsed from the pressure of the shifting river channel, killing eight motorists and sparking an investigation into the state's failure to inspect and correct problems with the bridge a decade earlier.

Thirty years later, as Tennessee Department of Transportation crews were busy fixing a partial bridge collapse on the Interstate 75 South overpass in Chattanooga that seriously injured one motorist, TDOT deputy commissioner and chief engineer Paul Degges remembered it was the anniversary of the Hatchie Bridge collapse.

While a National Transportation Safety Board investigation in 1989 cited the state as failing to correct problems found on the 54-year-old bridge from previous inspections, the partial bridge collapse onto the merging lanes of I-75 North to Interstate 24 West headed to Chattanooga almost two weeks ago was not due to negligence by state transportation officials but from an illegally oversized load that hit the bridge and cut through steel cables.

After Hatchie, Degges said the state moved toward an "asset management philosophy," which calls on the state to fix and maintain current roads and bridges before spending money building new ones. The philosophy has seemingly paid off.

In 2018, about 4.3% of bridges in Tennessee — or 871 of the 20,177 bridges — were considered "structurally deficient," meaning one of the key elements was in poor or worse condition. The share of bridges judged to be deficient in Tennessee was less than half the U.S. average and ranks Tennessee among the best states for bridge infrastructure, according to the 2019 report from the American Road & Transportation Builders Association.

Only nine states and the District of Columbia have fewer structurally deficient bridges than Tennessee. About 4.3% of bridges in Alabama and only 3.3% of bridges in Georgia are structurally deficient.

"I will say from a nationwide perspective, there is a big problem with bridge infrastructure out there, but for Tennesseans, and certainly for our state highway system, the bridges are in better shape now than they have been in [TDOT's] 100-year history."

While only 2.6% of the 8,300 bridges owned by TDOT are structurally deficient, 610 — or 5.3% — of the 11,400 owned by local governments across the state are considered structurally deficient, Degges said.

The national report states that in the 3rd Congressional District alone, 101 of the 1,902 bridges are structurally deficient — up from 84 bridges in 2014. Repairs are needed on 702 bridges, though, which will cost an estimated $254.5 million. The district includes Hamilton, Anderson, McMinn, Monroe, Morgan, Polk, Roane, Scott and Union counties and areas of Bradley and Campbell counties.

But while bridges are, for the most part, faring well in Tennessee, local municipalities are still feeling the strain of growing road congestion and not enough money to accommodate it all.

$3 billion needed locally

For just the Chattanooga-Hamilton County/North Georgia TPO, there is a combined funding shortfall of $1.7 billion for 18 road capacity projects, 14 transit capacity projects and three bicycle/pedestrian projects in the 2045 Regional Transportation Plan.

When the bridge collapsed on I-75, Thrive Regional Partnership released a statement about the bigger issue of needing to improve infrastructure in the region and across the country.

The nonprofit is focused on promoting responsible growth for the next 40 years through the tristate Chattanooga region, which includes working with 16 counties in three different states and the three different metropolitan planning organizations.

With transportation and mobility a large focus of the organization, officials often cite how the intersection of I-24 and U.S. Highway 27 is listed in the top 100 freight bottlenecks by American Transportation Research Institute.

"It's easy to complain about outdated roads and potholes, but we should be cognizant that our infrastructure is far past a Band-Aid solution," the nonprofit's officials said in a statement. "In reality, updates and maintenance is years behind."

Study to begin on Chattanooga area's traffic trends, needs

Freight movement and how the greater Chattanooga region will accommodate it in the future has been a concern for many local officials. By 2035, there will be an estimated 33 million tons of freight per year traveling through the area, up from 25 million in 2007.

Recently, TDOT was awarded a $250,000 grant from the Federal Highway Administration to study and project future freight volumes across the Chattanooga region and to identify regional needs and solutions.

TDOT will work with the Alabama Department of Transportation and the Georgia Department of Transportation, local metropolitan planning organizations, trucking companies and even McKee Foods and Thrive Regional Partnership on the study that does not have a start date yet.

TDOT and its 22 partners were one of only four projects nationwide that were selected for the grant. Projects in Phoenix, Arizona; Kansas City, Missouri; and Nevada were chosen, too.

The study also will look at the region's need for more truck parking and capacity, said Rhett Bentley, Thrive's communications manager.

The area to be studied covers portions of the three states and 6,648 miles total.

"This grant was only available for multi-jurisdictional and untraditional partnerships," Bentley said. "The grant is a tangible example of how leveraging unique partnerships can secure federal dollars."