Interstate 124 Tennessee


U.S. 27 lines a freeway north from Interstate 24 in Chattanooga to Soddy-Daisy and Tennessee 111 by Chickamauga Lake in southeastern Tennessee. The southern portion of the route, between I-24 and the Olgiati Bridge across the Tennessee River, doubles as unsigned Interstate 124. The interstate portion runs between Downtown and the Westside of Chattanooga.

The Mayor Peter Rudolph "Rudy" Olgiati River Bridge is a steel deck girder bridge spanning the Tennessee River from Downtown to Hill City. Mr. Olgiati was noted for several public works projects completed during his term including a second tunnel for McCallie Avenue (U.S. 11 & 64) through Missionary Ridge, widening of U.S. 27 along Rossville Boulevard and completion of the third Downtown bridge across the Tennessee River (named the Olgiati Bridge in 1959).1

Interstate 124 has disappeared and reappeared on the Tennessee Official State maps since 1986. The Tennessee Department of Transportation replaced most of the Interstate 124 signs in the mid-1990s due to some confusion among non-local motorists over the difference between I-24 and I-124.2 The route saw just one reassurance shield until 1999, with the addition of a second in the northbound direction. The 1999 Tennessee Official State Map again omitted Interstate 124 from both the state map and Chattanooga city inset. William Burmaster confirmed this change after a June 2003 visit to the area revealed no Interstate 124 shields or signs posted in either direction of U.S. 27.3 Furthermore William received an email response from the Tennessee Dept. of Trans in regards to I-124 that "Interstate 124 signs were not re-installed when the major directional interchange improvements [at I-24] were made some years ago."4

Another possible reason why TDOT dropped signs for Interstate 124 relates to the U.S. 27 freeway extension north of the U.S. 127/Signal Mountain interchange. Ironically enough, Scott Boles wrote in 2003 that the only portion of the U.S. 27 freeway in southern Tennessee that did not meet Interstate standards at the time was the section that was technically Interstate 124.


The section of Interstate 124 from Main Street to what is now Dr. Martin Luther King, Jr. Boulevard was constructed and opened to traffic by 1960. The connection from Interstate 24 north to Main Street was opened thereafter, probably in December 1966 in conjunction with the completion of the adjacent section of I-24 between the Georgia State Line and I-124.5

Expansion plans for U.S. 27 at Downtown Chattanooga in the 1990s included an option to replace the I-124 freeway with a tree-lined at-grade boulevard. The year long study completed by 1999 recommended an eight-lane boulevard acting as a gateway to Downtown with heavy landscaping, traffic lights and slower (35 mph) speeds.6 The $110-million TDOT plan would expand U.S. 27 from I-24 to Signal Mountain Road (U.S. 127) from four to six lanes and add collector distributor roads to the freeway at Downtown. The boulevard option, estimated to cost $29.9 million, drew concerns over funding. The Chattanooga-Hamilton County Regional Planning Agency indicated that if that option was chosen, state funding for the project would double from 10 to 20 percent, due to the removal of the Interstate designation. Additionally travel times were estimated to increase from 1 to 2 minutes on an expanded U.S. 27 (I-124) to 4 to 10 minutes on a boulevard.7

The boulevard option was never enacted upon and instead TDOT moved forward with plans to both widen and modernize the U.S. 27 freeway. William Burmaster adds that construction during June 2003 involved deck rehabilitation and improvements to the approaches for the 1959-built Olgiati Bridge over the Tennessee River.4 The $26.9-million project included provisions for eventual expansion of U.S. 27 between Downtown and the North Shore.8 Construction on the bridge started in February 1999 with an anticipated completion by June 2001. Setbacks due to utilities, right of way acquisition and materials resulted in delays through to 2003.9

Narrow shoulders and a tight curve south of the river remained after the Olgiati Bridge upgrade. Additionally the substandard Signal Mountain Interchange with U.S. 127 included tight ramps and no side lanes allocated for merging traffic.4 Early 2000s plans called for the continuing reconstruction of Interstate 124 and U.S. 27 both north and south of the Tennessee River. The second phase of work involved reconstructing and widening U.S. 27 from the Olgiati Bridge north to U.S. 127. The third phase was proposed to reconstruct U.S. 27 southward from the bridge to Interstate 24. Funds for both phases were programmed in Fiscal Years 2008 and 2009.10

Work finally commenced on the U.S. 27 reconstruction north of the river in December 2011. The $105.8-million project expanded 1.62-miles of the 1960s-built freeway to six and eight overall lanes. Included was construction of six new bridges, 33 retaining walls and redesign of interchanges with Manufacturers Road, Dayton Boulevard, and U.S. 127 (Signal Mountain Road). Work was slated for completion in October 2013, but the addition of an unplanned retaining wall over concerns for hill stability, pushed back completion to February 2015.11

Proposed spending of the US Department of Transportation for Fiscal Year 2002 included $2.4 million for a feasibility and planning study for an Interstate corridor between Chattanooga, Tennessee and Lexington, Kentucky. Designated as Interstate 175, the corridor followed the route of U.S. 27 and may have incorporated via the U.S. 27 freeway from I-24 to Soddy-Daisy. The final Transportation spending bill passed by the U.S. House of Representatives and Senate in late 2001 however did not include funding for the route.12

Planned Improvements

The final phase of U.S. 27 (I-124) reconstruction by Downtown Chattanooga, estimated to cost $98 million in 2012,8 was planned to run in tandem with work north of the river through to 2017.11 Opposition during the Urban Design Challenge presentation for the Fourth Street corridor regarding pedestrian accessibility previously halted work in 2012.6 Uncertainty of available funds from the Highway Trust Fund further delayed the project in 2015.11

The contract to bring Interstate 124 to modern safety standards was eventually awarded by November 2015 at $126.3-million, the most expensive project in TDOT history. Construction includes the redesign of interchanges with Martin Luther King Boulevard and 4th Street, the elimination of the S-curve at 4th Street, and new frontage roads. Additionally crews will expand the Olgiati Bridge by a lane in each direction. Design work on this project started in 2006 with right of way purchased in 2015.13 Work on the 2.3-mile project is targeted for completion on July 31, 2019.8

For project details, see the U.S. 27 Reconstruction in Downtown Chattanooga - TDOT web site.

Southern Terminus - Interstate 24 - Chattanooga, Tennessee
Perspective from Interstate 124/U.S. 27 south
Milepost one appears as Interstate 124 & U.S. 27 curve southwest over 12th Street. An unnumbered three-wye interchange joins the freeway with Interstate 24 in 0.75 miles.
Construction here from 2016-19 expands the southbound freeway between three and five lanes. Photo taken 01/21/13.
Lookout Mountain, home to Chickamauga and Chattanooga National Military Park, rises to the south as Interstate 124 & U.S. 27 wind southwest across Main Street and Riverfront Parkway. Forthcoming I-24 east ends in seven miles at Interstate 75. Westbound I-24 straddles Raccoon Mountain south into north Georgia. Photo taken 01/21/13.
U.S. 27 departs Interstate 124 for Interstate 24 east and a two-mile overlap; note that these signs do not advise of the U.S. 27 southbound continuation. The US highway leaves the Interstate system at Exit 180 for Rossville Boulevard to East Lake/Clifton Hills and Rossville, Georgia. Photo taken 01/21/13.
U.S. 27 south joins a c/d roadway along Interstate 24 east at the off-ramp for U.S. 11-41-64-72 (Broad Street) at Southside Chattanooga. The US routes lead motorists south to Alton Park and St. Elmo in Chattanooga and Lookout Mountain to the west. Photo taken 01/21/13.
Milepost zero for the U.S. 27 freeway stands at the gore point connecting I-124 south with the eastbound c/d roadway (Exit 178) of Interstate 24. Photo taken 01/21/13.
Historical Perspective from Interstate 124 & U.S. 27 south
This diagrammatic sign replaced a pair of separate panels for Interstate 24 on the curve preceding the Main Street on-ramp. The overhead here was damaged when a vehicle struck the left side of the sign by 2007. A replacement was made by 2008. Photo taken 06/18/05.
Perspective from Interstate 24 west
U.S. 27 north combines with Interstate 24 from Rossville Boulevard for a brief overlap west to unsigned Interstate 124 (Exit 178). Photo taken 06/25/12.
A distributor roadway (Exit 178) handles movements to Market Street north to Downtown and 21st Street west to U.S. 11-41-64-72 (Broad Street) for Lookout Mountain in addition to the U.S. 27 freeway leading north to Hill City and Soddy-Daisy. Beyond Interstate 124, I-24 travels westward 11 miles to the northern terminus of Interstate 59. Photo taken 06/25/12.
Three lanes separate from the Interstate 24 westbound mainline for U.S. 27 & I-124 north to Downtown Chattanooga. Back to back ramps quickly depart for Market and 21st Streets while U.S. 27 north parallels I-24 west through to Chestnut Street. Photo taken 06/25/12.
Continuing west on the c/d roadway, the next off-ramp connects with Tennessee 58 (Market Street) north to adjacent U.S. 11 & 64 (20th Street) at Southside Chattanooga. U.S. 27 north stays west another 0.6 miles along side I-24 to I-124. Photo taken 06/18/05.
A loop ramp follows onto Tennessee 58 (Market Street) south through Alton Park in Chattanooga and 21st Street west to U.S. 11-41-64-72 (Broad Street). The four-way US route overlap lines Broad Street south to St. Elmo, where they turn west to encircle Lookout Mountain. Photo taken by Chris Patriarca (07/14/03).
Perspective from Interstate 24 east
Interstate 24 eastbound straddles the Tennessee River to the south of Moccasin Bend on the two mile approach to Interstate 124 and U.S. 27 (Exit 178). Photo taken 11/03/11.
Interstate 24 runs between the Tennessee River and the L and N Railroad, which disappears at the Lookout Mountain Tunnel through the adjacent rock facade. A diagrammatic sign outlines the forthcoming split with Exit 178 for U.S. 27 (I-124) north and Broad Street (U.S. 11-41-64-72) to Downtown Chattanooga. Photo taken 11/03/11.
Swinging northward through industrial Southside in Chattanooga, Interstates 24 and 124 will separate with two lanes serving each route. Photo taken 11/03/11.
Exit 178 departs as a collector distributor roadway for Interstate 124 & U.S. 27 north to Westside, Downtown and Hill City across the Olgiati Bridge and U.S. 11-41-64-72 (Broad Street) at Southside. U.S. 27 south combines with I-24 east through to Rossville Boulevard at East Lake/Clifton Hills. Photo taken 11/03/11.
Exit 178 leaves Interstate 24 east for I-124 & U.S. 27 north and U.S. 11-41-64-72 (Broad Street). I-24 ends in 7.3 miles at Interstate 75. Photo taken 11/03/11.
Passing over the L and N Railroad, Exit 178 separates into single lane ramps for U.S. 27 north and the c/d roadway east to Broad Street. U.S. 27 joins Chattanooga with Signal Mountain via U.S. 127 at Red Bank and Soddy-Daisy as a full freeway. U.S. 11-41-64-72 combine at Tiftonia to parallel I-24 east through to Southside Chattanooga. There U.S. 72 ends and U.S. 76 begins, while U.S. 11-64 and 41 turn east through the Highland Park/Oak Grove neighborhood parallel to I-24. Photo taken 11/03/11.
Perspective from Interstate 124 north
This Interstate 124 reassurance marker was posted by November 1999 and located on the transition ramp from I-24 east to U.S. 27 north. Removed by 2003, it was the lone northbound shield at the time. Photo taken by Philip Hart (11/21/99).
Northern Terminus - P.R. Olgiati Bridge over the Tennessee River - Chattanooga, Tennessee
Perspective from Interstate 124 and U.S. 27 north
The trumpet interchange (Exit 1C) joining Interstate 124 & U.S. 27 with Fourth Street (note the greenout of Tennessee 58 on signage) will redesigned into a modified diamond interchange as part of the U.S. 27 reconstruction at Downtown Chattanooga. 4th Street otherwise connects the freeway with the north end of Downtown. Photo taken 01/21/13.
Moving through the S-curve at 4th Street, the four-lane U.S. 27 freeway has virtually no shoulders and a barrier median as it passes by AT&T Park. Expansion here from 2016-19 widens I-124 to six lanes over 4th Street and eight lanes across the Olgiati Bridge. Photo taken 01/21/13.
Interstate 124 ends as U.S. 27 continues north across the Mayor Peter Rudolph "Rudy" Olgiati River Bridge over the Tennessee River. Subsequent interchanges are unnumbered as U.S. 27 ventures north to Hill City in Chattanooga and Red Bank. Photo taken 01/21/13.
Perspective from U.S. 27 south
U.S. 27 south crosses the Tennessee River from Hill City to Downtown and Westside Chattanooga on the Olgiati Bridge. The freeway winds southward to 4th Street (Exit 1C) and Martin Luther King, Jr. Boulevard (Exits 1B/A) as unsigned Interstate 124. Photo taken 01/21/13.
Interstate 124 begins as U.S. 27 approaches the trumpet interchange (Exit 1C) with 4th Street (Tennessee 58) east into Downtown. Note that Tennessee 58 is acknowledged on signs in this direction but is omitted along northbound. The route is unmarked along 4th Street as well. Photo taken 01/21/13.
Perspective from Interstate 124 and U.S. 27 south
The Downtown Chattanooga skyline comes into view as Interstate 124 & U.S. 27 enter the S-curve by AT&T Field and 4th Street. The curve here will be straightened out during construction from 2016-19. Photo taken 01/21/13.
Posted immediately after the P.R. Olgiati Bridge, this was the lone remaining southbound reassurance marker for Interstate 124. It was located next to a former ground level sign for Exit 1C. Photo taken by Jim K. Georges (05/98).
Back to back ramps for Tennessee 58 (Exit 1C) and Martin Luther King Boulevard west (Exit 1B) will be consolidated into a single ramp as part of the U.S. 27 reconstruction during 2016-19. The loop ramp (Exit 1A) for Martin Luther King Boulevard east into Downtown will be retained. Photo taken 01/21/13.


  1. 1951-1963 Peter Rudolph "Rudy" Olgiati, city of Chattanooga web site.
  2. "No Signs, But It's Still There." Chattanooga Times Free Press (TN), September 2, 1998.
  3. William Burmaster, email: "I-124" July 1, 2003.
  4. William Burmaster, email: "Fwd: FW: just a question" September 10, 2003.
  5. Chattanooga Flag Map (1960), originally posted on the Interstate 50th Anniversary web site
  6. "Boulevard Proposal Studied for U.S. 27." Chattanooga Times Free Press (TN), April 19, 1999.
  7. "state officials explain their concerns to city planners." Chattanooga Times Free Press (TN), July 5, 1998.
  8. "BIG ROAD REMAKE - U.S. 27 REBUILD FROM OLGIATI TO I-24 ABOUT TO BEGIN." Chattanooga Times Free Press (TN), November 15, 2015.
  9. "Another setback for Olgiati? - Bridge work could stretch through 2003." Chattanooga Times Free Press (TN), July 13, 2002.
  10. Fiscal Years 2007-2009 Transportation Improvement Program (as of 05/23/06) - under Hamilton County: Interstate 124/U.S. 27 were proposed for preliminary engineering and right of way acquisition funding for additional lanes from north of Interstate 24 to south of the Tennessee River Bridge, a distance of 1.5 miles.
  11. "SMOOTH SAILING AHEAD - The three-year project to rebuild U.S. 27 led to some rough patches for motorists. But at last, completion is at hand." Chattanooga Times Free Press (TN), January 5, 2015.
  12. - Interstate 175 (Jeffrey Carlyle)
  13. "2 Traffic Lanes To Be Left Open Each Way During Construction Of $126 Million Downtown Freeway Makeover Featuring "Monster Wall"." The Chattanoogan, January 7, 2016.

Page Updated January 12, 2016.