Like dark omens, electronic and new steel signs sit on Chattanooga's North Terrace and South Terrace, foretelling the coming closure and detours in the replacement of the bridges over Interstate 24 at South Moore and McBrien roads now looming in the middle of next week.
For residents of the city of East Ridge and Chattanooga's Brainerd community, the coming change to the traffic pattern on North and South terraces and at Spring Creek Road and Belvoir Avenue is significant as the first piece of the $161 million phase 2 of the Interstate 75/I-24 reconstruction project officially gets started.
Preparations for the bridge closures begin Friday night when the off-ramp from I-24 to Moore Road and for westbound Belvoir Avenue will be closed. On Wednesday, the on-ramp from North Terrace to I-24 west and from South Terrace to I-24 east will be closed along with the bridges, and traffic challenges will be in place for the coming months.
"A 'continuous-flow' detour loop around the terraces will be put in place prior to the bridge closures, which requires some paving and striping," Tennessee Department of Transportation spokesperson Rae Anne Bradley said Thursday in an email. "The contractor will have one year to complete construction of both the South Moore Road and McBrien Road bridges."
Bradley said the detour will be created with a new traffic pattern.
The closure of the bridges on Wednesday will happen around 9 a.m. at the end of the morning rush, according to a city of East Ridge news release issued Thursday. All of the work is weather dependent, East Ridge spokesperson Bridgett Raper said in the release.
According to the general description of bridge work and detours, the traffic signals at South Moore and North Terrace; McBrien and North Terrace; South Moore and South Terrace; and McBrien Road and South Terrace will all be disabled while the bridges are closed.
North Terrace and South Terrace will be repaved and restriped so the left lane and center lane become through lanes and the right lanes on the terraces become right-turn-only lanes, according to Bradley. The left lanes of North Terrace and South Terrace will be used for the "contraflow" movement of detoured traffic. The term contraflow refers to the flow of traffic, in this case, on the nearest lanes to the interstate to make the detour loop continuous.
Signs will direct truck traffic on a slightly different route but with the same destinations, according to plans.
MCBRIEN ROAD TRAFFIC PATTERNS
This animation shows the flow of traffic from northbound McBrien Road — leaving East Ridge — leading onto South Terrace with connections for Interstate 24.
This animation shows the flow of traffic from northbound McBrien Road — leaving Brainerd — leading onto North Terrace with connections for Interstate 24.
"This will allow free-flow movements through those intersections," she said.
At Belvoir Avenue and North Terrace, the Belvoir Avenue bridge over I-24 will be temporarily restriped to allow a continuous contraflow U-turn across the bridge for the left lane of North Terrace, while the center lane and right lane will go through the signal like normal, Bradley said.
Similarly, at Spring Creek Road and South Terrace, the Spring Creek Road bridge will be temporarily restriped to allow a continuous contraflow U-turn across the bridge for the left lane of South Terrace, while the center lane and right lane will go through the signal as it typically does.
"The on- and off-ramps between Belvoir and Moore will be closed while the continuous flow detour is in effect. This is to maintain safe and efficient operation of I-24, when work begins in the fall, and the detour. Additionally, the ramps will be rebuilt while they are closed," Bradley said. "For I-24 west, traffic will use the South Moore exit to leave the interstate and the South Germantown entrance to access the interstate. Similarly, for I-24 east, traffic will use the South Germantown exit to leave the interstate and South Moore entrance to access the interstate."
SOUTH MOORE ROAD TRAFFIC PATTERNS
This animation shows the flow of traffic from northbound South Moore Road — leaving East Ridge — leading to South Terrace and connections for Interstate 24:
This animation shows the flow of traffic from southbound South Moore Road — leaving Brainerd — leading to North Terrace and connections for Interstate 24:
Ooltewah resident Vanetta Perry said she would make an effort to avoid having to use the terraces to get to East Ridge or Brainerd, but she's pleased with the way the first portion of the split project turned out.
"I am thrilled beyond belief with the way they put that back," Perry said Thursday of phase 1 in a phone interview. "It's all finished coming out of Georgia, and thank goodness for that."
Perry, a bit dubious of the detours, said if she has to visit Brainerd she plans to use Brainerd Road, and if she's headed to East Ridge she'll get off at Exit 1.
Bradley said the continuous flow detour design is an innovative approach that allows construction of the bridges on South Moore and McBrien road to be reduced from two years of traffic effects to one year. While phase 2 of the split project continues toward a 2025 completion date, drivers will have to be cautious and aware of changes due to construction on North and South terraces and the interstate.
DRIVER PERSPECTIVES OF TRAFFIC FLOW CHANGES
This animation shows a driver's perspective of traffic flow along North Terrace approaching Belvoir Avenue.
This animation shows a driver's perspective of traffic flow from Georgia on Interstate 75 approaching the I-24/I-75 interchange.
"As with any major interstate construction project, drivers will at times be impacted by noise, lane closures and delays during construction. Interstate lanes will feel narrow to drivers, shoulder widths will be reduced during construction due to limited space," Bradley said. "However, the interstates will remain open at all times."
Three lanes of I-24 and I-75 — where more phase 2 work is coming in the current project — will remain open in each direction, Bradley said, with some exceptions.
There will be nighttime lane closures Sunday through Thursday, six weekend lane closure events on I-24 and 10 weekend closure events on I-75 between now and the end of the project in 2025, according to TDOT.
"The dates of the weekend events have not yet been scheduled but will be announced well in advance," Bradley said. "Drivers are encouraged to reduce their speed and drive with caution through the work zone. Construction equipment and personnel will be on-site around the clock, working to complete the project as safely and efficiently as possible."
Bradley said motorists and commuters with questions can go to the FAQ page on TDOT's project website at bit.ly/phase2FAQ.
TDOT officials remind motorists to pay attention and slow down when driving through construction work zones and to move over for vehicles with flashing lights.