A major Tennessee transportation project aimed at easing chronic traffic congestion between Dade County and Chattanooga is expected to cost significantly more than originally planned, according to state transportation officials.
The Tennessee Department of Transportation (TDOT) says the long-discussed Interstate 24 widening and interchange improvement project remains a priority, even as projected costs continue to rise.
During Hamilton County Mayor Weston Wamp’s recent State of the County address, TDOT Commissioner Will Reid said the estimated cost to improve the Interstate 24 and U.S. Highway 27 interchange near downtown Chattanooga — commonly referred to as the Moccasin Bend Widening Project — has increased by approximately $300 million.
“To really get what we need to fix that area, we need about $300 million more,” Reid said.
Last year, TDOT announced that $246 million had already been allocated for engineering and right-of-way acquisition connected to the project. Officials now say inflation and rising construction costs following the COVID-19 pandemic have dramatically increased the overall price of highway infrastructure work.
“When I first started out as a young engineer, the rule of thumb would be $1 million a mile,” Reid said. “As I sit here today, it’s between $20 and $50 million a mile to build a highway project.”
The project targets one of the most heavily traveled and congested corridors in the Chattanooga region. Plans call for widening a roughly 10-mile stretch of Interstate 24 from Interstate 59 in Dade County, Georgia, to U.S. Highway 27 near downtown Chattanooga.
The expansion would increase the interstate from four lanes to six while also widening shoulders and travel lanes to 12 feet. TDOT officials say 14 bridges will either be replaced or upgraded as part of the project, including 12 bridges in Tennessee and two in Georgia.
Robbie Hayes with Nashville-based infrastructure firm HNTB said the work is designed to improve traffic flow and address aging infrastructure.
“We’re trying to help improve congestion,” Hayes said, noting several bridges along the corridor have received “fair” or “poor” inspection ratings.
Engineer Justin Eckel said additional improvements will include upgraded guardrails, barrier walls and retaining walls designed to meet modern highway safety standards.
Because of the corridor’s unique geography — bordered by the Tennessee River, railroad lines and nearby bluffs — TDOT says several design concepts are being evaluated to maximize available space.
“We’ve talked about double-decking the interstate,” Reid said. “There’s a lot of things that we’re looking at. Managed lanes or choice lanes is one of those tools that we’re looking at.”
The project will be divided into three phases:
- Segment 1: Interstate 59 to the Tennessee state line
- Segment 2: Tennessee state line to Browns Ferry Road
- Segment 3: Browns Ferry Road to U.S. Highway 27
Daily commuters say improvements are badly needed, especially near the downtown Chattanooga “ridge cut” and “bends” areas that are frequently backed up during peak travel times.
“The traffic is basically stopped in those two lanes,” Chattanooga commuter Giselle Palmer said. “Another lane could really help alleviate some of that.”
Others believe road widening alone will not fully solve long-term transportation problems in the region.
Kat Volzer, a supporter of expanded transit alternatives, said multimodal transportation solutions should also be considered.
“I’m cool if they add another lane — not a big deal — but we need to go back to that multimodal,” Volzer said. “That’s really what’s going to alleviate traffic, especially for those residents in Lookout Valley who want to get to downtown.”
TDOT says additional environmental and technical studies are expected over the coming months as planners continue refining the project. Officials anticipate another round of public input opportunities in early 2026.
Construction is currently expected to begin in late 2027 or 2028. A final completion timeline has not yet been announced.