Georgia motorists on Interstate 75 North, headed onto Interstate 24 through the infamous "Split," will have to make a lane choice a quarter mile sooner, with a new traffic pattern going into place this week as the $132.6 million interchange modification project keeps rolling.
While the new pattern is a surprise for drivers on I-75, people stopping off at the state Welcome Center just inside the Tennessee state line will find their path to I-24 completely cut off. That's because the Split's old I-75 North lanes are history and the I-75 to I-24 West dividing point temporarily is several hundred yards closer to exit 1.
Now, Welcome Center drivers heading for I-24 will have to take a new I-75 North all the way to the East Brainerd West exit to reverse course back to the Split and I-24 West, according to Tennessee Department of Transportation spokeswoman Jennifer Flynn. Detour instructions are posted at the Welcome Center, she said.
The traffic pattern change could even affect drivers in East Ridge heading for I-24 from I-75's exit 1, who could find themselves on the same detour, especially when traffic is heavy at the ramp from westbound Ringgold Road onto I-75 North in front of Bass Pro Shops and traffic backs up from the I-75-to-I-24 West bottleneck.
The detour to East Brainerd Road and back to the Split is about six miles.
More than 100,000 vehicles a day travel the notorious interchange, known for its daily backups, antiquated merge lanes and frequent crashes. The interchange and area interstates were built in the late 1950s and early 1960s.
The project consists of widening existing roads and ramps, increasing the radius of ramps, reconfiguring entrance and exit ramps on I-75, shifting the interchange to the west and modifying the Tennessee Welcome Center area traffic circulation, according to TDOT. The project includes new bridges for Spring Creek Road over I-24, as well as interstate bridges throughout the interchange area.
The Split is one of two Chattanooga area interchanges to make the list of the country's 100 worst bottlenecks by the American Transportation Research Institute, the other interchange being the I-24 to U.S. Highway 27 for downtown Chattanooga. Neither of the interchanges ended up in the national top 20, at least, but TDOT Commissioner John Schroer in June 2017 called the Split "about the worst interchange in the state of Tennessee."
Construction started in May 2018.
BY THE NUMBERS
$132.6 million: Estimated price tag
2,100: Number of individual work activities planned to complete project
5: Bridges over Spring Creek
2: Bridges on Spring Creek Road over I-24 including interstate to interstate ramps, five bridges over Spring Creek and two bridges on Spring Creek Road over I-24
4: Interstate to interstate bridges over roadways
Source: Tennessee Department of Transportation
What's new is the just-completed ramp northbound I-75 traffic takes through the interchange on a new, two-lane road east of the existing interchange footprint and closer to the edge of East Ridge's Camp Jordan. This stretch of road will serve as the temporary mainline of I-75 North, Flynn said.
When the interchange project is finished next summer, this piece of road will become the ramp that takes traffic to I-75 North from East Ridge exit 1 and the Welcome Center.
Flynn said the lingering problem of getting to I-24 from East Ridge's exit 1 is made a little tougher with the current pattern change, but it'll be easier as drivers gain experience.
"[T]he issue is that at times I-75 lanes are free flowing where I-24 is bottle necking at the interchange," Flynn said. "This is creating a speed difference making it hard to jump over into those lanes unless you find a gap.
"Hopefully, people will get used to the new traffic pattern soon," she said. "It's always a challenge on the first day after we make a major change to a project. Also, there was a multiple vehicle crash on I-24W [Wednesday] shortly before lunchtime and it made traffic worse. Fortunately it was cleared relatively quickly."
Welcome Center Detour InstructionsView
Watch for trucks entering and exiting project. Traffic should expect multiple lane shifts traveling through the interchange. Lane closures will occur Sunday nights through Thursday nights between 9 p.m. and 6 a.m. at the following locations: I-75 northbound mile marker 1, I-75 southbound mile marker 3 and I-24 eastbound mile marker 184. Traffic pacing may occur throughout interchange Sunday nights through Thursday nights between 9 p.m. and 6 a.m. Additionally, there could be intermittent shoulder closures at various locations for access to the median and roadside areas. Welcome Center traffic intending to use I-24 West now will have to detour on I-75 NB to Exit 3. Detailed detour information will be available at the Welcome Center. The speed limit has been reduced to 45 MPH throughout the interchange.
Source: Tennessee Department of Transportation weekly Roadway Activity Report - Region 2 for July 16-22, 2020
Drivers on the new, temporary I-75 North path will find the new curve much less dramatic and easier to negotiate than the old one that has been abandoned. It's an example of what's to come in the redesigned interchange while it makes way for the contractor to move to the next step, according to TDOT leaders.
"This new traffic pattern will allow the contractor to construct new ramps and bridges in the center of the interchange," TDOT Region 2 Director Joe Deering said in an emailed statement. "When finished later this year these new ramps will tie I-75 to I-24, and the contractor will then be able to complete the final phases of the project."
The interchange will have increased capacity and meet current design standards and "improve overall operational efficiency of the interchange," Deering said.
In recent months, major features of the project started to take shape with construction of some of the bridge structures for the I-24 link to I-75 North and I-75 North's redesigned future link to I-24 West in the project slated for completion in late summer 2021, according to TDOT. Marietta, Georgia-based C.W. Matthews Contracting Co. Inc. is the contractor on the project.
Now, northbound drivers on I-75 headed for downtown Chattanooga, Nashville and Alabama pile into the two left-hand lanes to bottleneck into a two-to-one lane merge onto I-24 West. The awkward merge that creates a massive daily backup sometimes south into Georgia will be addressed by the last phase of the project, Flynn said.
"When we reach the third and final phase of construction, the I-24 westbound ramp will actually be exiting right, this is reverse of the current configuration," Flynn said. "This I-24 West ramp will elevate up and over the future I75 North and South with a flyover bridge. I-75 will become a more traditional mainline flowing through the center of the interchange with traffic in the left lanes to continue north."
Aside from the redesign of the Split, there's also a $32.9 million project underway within a mile that will replace the bridges over I-24 at Belvoir Avenue and on I-24 over Germantown Road. The construction manager for that work is Bell & Associates Construction and the design manager is Barge Design Solutions.
TDOT officials estimate the bridge replacement projects will be complete in the first half of 2021, followed by completion of the interchange project in late summer, so the hated orange barrels will hang around for another year or so.
Contact Ben Benton at email@example.com or 423-757-6569. Follow him on Twitter @BenBenton or at www.facebook.com/benbenton1.