U.S. 27 lines a freeway north from the Big Scramble Interchange with Interstate 24 in Chattanooga to Soddy-Daisy and Tennessee State Route 111 by Chickamauga Lake in southeastern Tennessee. The southern portion of the route, between I-24 and the Olgiati Bridge, doubles as unsigned Interstate 124. The interstate portion runs between Downtown and Westside Chattanooga.
The Mayor Peter Rudolph “Rudy” Olgiati River Bridge is a steel deck girder bridge spanning the Tennessee River from Downtown to Hill City. 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 There was one remaining reassurance shield until 1999, when a second marker was added in the northbound direction. However 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 Deptartment of Transportation (TDOT) regarding I-124:4
Interstate 124 signs were not re-installed when the major directional interchange improvements [at I-24] were made some years ago.
Another possible reason why TDOT dropped signs for Interstate 124 was due to the northward extension of the U.S. 27 freeway beyond the Signal Mountain interchange with U.S. 127. 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 assigned to Interstate 124.
The final phase of U.S. 27 (I-124) Reconstruction in Downtown Chattanooga, estimated to cost $98 million in 2012,8 was planned to run in tandem with work north of the river to 2017.11 Work was previously halted in 2002 due to opposition during the Urban Design Challenge presentation for the Fourth Street corridor regarding pedestrian accessibility.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. It was the most expensive project in TDOT history at the time. 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 and rights of way were purchased in 2015.13 Work on the 2.3-mile project wastargeted for completion on July 31, 2019,8 but later amended to January 2020.
Work on the northbound lanes for I-124/U.S. 27 was completed first, allowing crews to shift southbound traffic to the new roadway with two-way traffic. Construction on the southbound lanes, the new exchange at 4th Street and MLK Boulevard continues from 2018 to 2019. Final paving and striping work was to be completed from late 2019 to January 2020, but continued into March 2020.
North End – Chattanooga, TN
South End – Chattanooga, TN
Mileage – 1.97
Cities – Chattanooga
- Junctions –
Source: December 31, 2018 Interstate Route Log and Finders List
I-124 Annual Average Daily Traffic (AADT)
Interstate 124 opened initially between West 9th Street (M.L. King Boulevard) and the Olgiati Bridge. By 1964, I-124 was extended southward to the new stretch of I-24 leading east.
As approved by AASHTO on June 26, 1985, U.S. 27 was relocated from the surface route between East Lake/Clifton Hills in Chattanooga to Red Bank onto an overlap with I-24 through Southside and I-124 by Downtown.
The interstate portion of U.S. 27 never extended all the way to U.S. 127 (a distance of approximately four miles), even though the Rand McNally Northern American Road Atlas from 1980 to 1987 mistakenly showed it beyond the Tennessee River. I-124 was removed from the Chattanooga inset in the 1988 edition.
The section of Interstate 124 from Main Street to 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, likely in December 1966 in conjunction with the completion of I-24 between the Georgia State Line and I-124.5
1990s Expansion plans for U.S. 27 at Downtown Chattanooga 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, signalized intersections and slower (35 mile per hour) speeds.6 The $110-million TDOT plan would expand U.S. 27 between I-24 and 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, due to the removal of the Interstate designation, state funding for the project would double from 10 to 20 percent. Additionally estimated travel times were forecast 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 added that construction during June 2003 involved deck rehabilitation and improvements to the approaches for the Olgiati Bridge.4 The $26.9-million project included provisions for eventual expansion of U.S. 27 between Downtown and the North Shore.8 With an anticipated completion by June 2001, construction on the span started in February 1999. Setbacks due to utility work, right of way acquisition and materials resulted in delays 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 ramps with sharp geometry and no side lanes allocated for merging traffic.4 Early 2000s plans outlined 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 omitted funding for the route.12
North End / P.R. Olgiati Bridge – Chattanooga, Tennessee
Construction consolidated the succeeding ramps for SR 389 / 4th Street (Exit 1C) and Martin Luther King Boulevard west (Exit 1B) into a single ramp as part of the U.S. 27 Reconstruction in Downtown Chattanooga project. The loop ramp (Exit 1A) for Martin Luther King Boulevard east into Downtown is retained. 01/21/13
South End – Chattanooga, Tennessee
Lookout Mountain, home to Chickamauga and Chattanooga National Military Park, rises to the south as I-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. 01/21/13
A distributor roadway (Exit 178) separates traffic from I-24 west to Market Street north for Downtown, 21st Street west for U.S. 11-41-64-72 (Broad Street) to Lookout Mountain and the U.S. 27 freeway leading north to Hill City and Soddy-Daisy. Beyond Interstate 124, I-24 travels westward 11 miles to the north end of I-59. 06/25/12
A loop ramp follows onto SR 58 (Market Street) south through Alton Park in Chattanooga and 21st Street west to U.S. 11-41-64-72 (Broad Street). The four US routes overlap along Broad Street south to St. Elmo, where they turn west to encircle Lookout Mountain. Photo taken by Chris Patriarca (07/14/03).
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. 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 and parallel I-24 east 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 adjacent to I-24. 11/03/11
- 1951-1963 Peter Rudolph “Rudy” Olgiati, city of Chattanooga web site.
- “No Signs, But It’s Still There.” Chattanooga Times Free Press (TN), September 2, 1998.
- William Burmaster, email: “I-124” July 1, 2003.
- William Burmaster, email: “Fwd: FW: just a question” September 10, 2003.
- Chattanooga Flag Map (1960). Interstate 50th Anniversary web site
- “Boulevard Proposal Studied for U.S. 27.” Chattanooga Times Free Press (TN), April 19, 1999.
- “state officials explain their concerns to city planners.” Chattanooga Times Free Press (TN), July 5, 1998.
- “BIG ROAD REMAKE – U.S. 27 REBUILD FROM OLGIATI TO I-24 ABOUT TO BEGIN.” Chattanooga Times Free Press (TN), November 15, 2015.
- “Another setback for Olgiati? – Bridge work could stretch through 2003.” Chattanooga Times Free Press (TN), July 13, 2002.
- Fiscal Years 2007-2009 Transportation Improvement Program (as of 05/23/06)
http://www.tdot.state.tn.us/roadprojects/road/default.htm– 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.
- “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.
- KentuckyRoads.com – Interstate 175 (Jeffrey Carlyle)
- “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 March 13, 2020.