Interstate 640 – Tennessee
Interstate 640 encircles central Knoxville to the north. The freeway bypasses Downtown and the University of Tennessee.
Overview
Interstate 640 through Knoxville is an urban loop serving both long distance and freight traffic along I-40 and I-75 north to Kentucky. Additionally the bypass is the mandatory route for trucks carrying hazardous materials across the city. Running on the north side of Sharp Ridge, the six lane freeway also serves commuter traffic from the Fountain City community and other suburban areas of Knoxville.
I-75 overlays the western leg of I-640 for 3.60 miles between I-40 by Marble City and I-275/U.S. 25W at Inskip. I-640 measures 10.8 miles in length, but only the portion east of I-75 is attributed to it within the Federal Highway Administration (FHWA) Route Log and Finder List.
History
The State of Tennessee Department of Highways and Public Works included Interstate 640 in its list of proposed urban Interstate numerology to the American Association of State Highway Officials (AASHO) on August 15, 1958. AASHO approved all submissions in a letter dated on November 12, 1958.
Route Information
East End – Knoxville, TN
West End – Knoxville, TN
Mileage – 7.03
Cities – Knoxville
- Junctions –
Source: December 31, 2018 Interstate Route Log and Finders List
I-640 Annual Average Daily Traffic (AADT)
Source: 2018 Traffic Map – Knox County, Tennessee Department of Transportation
Construction for the Knoxville northern bypass commenced October 1977 with an anticipated completion date of April 1982. While construction was underway the Tennessee Department of Transportation (TDOT) mailed proposed changed for the Knoxville Interstate system to the Federal Highway Administration (FHWA) Division Administrator on November 29, 1979:
The Tennessee Department of Transportation desires to relocate Interstate 75 in Knoxville along the western leg of I-640 as described in the attached report. The relocation would occur from the proposed I-75/I-640 directional interchange north of the Knoxville CBD to the I-640 junction with I-40 west of Knoxville. The Department also wishes to designate the section of existing I-75 from the I-640 directional interchange to the I-40 directional interchange in downtown Knoxville as I-275
The FHWA Division Administrator in Nashville recommended approval of the request on December 11, 1979. The relocation of I-75 was desired to reduce the trip length by two miles for through traffic and remove a large number of vehicles from the downtown area of Knoxville. Additionally, multi year reconstruction of I-40 from I-640 at milepost 385.50 to the exchange with I-75 at milepost 388.00 caused lengthy traffic delays due to construction activity. It was assumed that the state wanted to keep I-640 designated on the western leg with I-75 for the convenience of through traffic avoiding congestion along I-40 in the downtown area.
The Federal Highway Administration (FHWA) concurred with TDOT’s proposal on December 18, 1979. This was subject to the proper route description and mileage for revised I-640:
We support continuance of I-640 signing on the west leg of the loop, overlapping with I-75 with dual numbering, for the benefit of I-40 bypass traffic. However, we believe that the official route description and mileage for revised I-640 should cover only the east leg of the loop, “…from a junction with FAI Routes 75 and 275 … to a junction with FAI Route 40…,” 6.5U miles (10.1 – 3.6).
This was further clarified in correspondence from the FHWA Regional Federal Highway Administrator to TDOT on January 2, 1980:
Rather, the west leg of present I-640 should become a portion of I-75. The State is free, however, to place I-640 trailblazer signs on that section as well as on I-40 west of the interchange with renumbered I-75. Interstate 640 would then be from I-75/I-275 to I-40 in northeast Knoxville.
The application rerouting I-75 over I-640 and establishing Interstate 275 was approved by the American Association of State Highway and Transportation Officials (AASHTO) on June 24, 1980. The western leg of Interstate 640 was scheduled to open in December 1980.
Costing $22.22 million, work at the Broadway/I-640 interchange through Spring 2019 completed improvements at the exchange started in 2016. This work was the second phase of a long term project originating in 1999. Finished then were new ramps along the eastbound direction of I-640 at U.S. 441 (Broadway). The final phase added a loop ramp from U.S. 441 (Broadway) north to I-640 west and a collector roadway eliminating weaving traffic along U.S. 441 southbound from Tazewell Pike (SR 331).1
Highway Guides
East End 
– Loveland, Knoxville, Tennessee
East 
South at 
I-640/U.S. 25W east cross a ridge by the Loveland neighborhood ahead of the directional T interchange with I-40. Photos by Carter Buchanan (10/15/11).
I-640 concludes with two lane ramps joining I-40/U.S. 25W north to Dandridge and Asheville, North Carolina and I-40 west back into central Knoxville. Photo by Carter Buchanan (10/15/11).
West North at
U.S. 25W northbound combines with I-40 west for 1.01 miles from U.S. 11E/70 (Asheville Highway) to connect with I-640 west at Exit 393. 06/25/12
Interstate 40 westbound maintains three lanes through the exchange with I-640. U.S. 25W overlaps with I-640 westward to I-75, where it shifts northwest from Norwood to the Anderson County seat of Clinton. Photo by Carter Buchanan (06/10/17).
Exit 393 separates from I-40 west for I-640/U.S. 25W to I-75 north for Lexington, Kentucky. Downtown Knoxville lies five miles ahead along Interstate 40. 06/25/12
East at
I-40 advances east by Zoo Knoxville to a parclo interchange (Exit 392) with U.S. 11W (Rutledge Pike) and I-640/U.S. 25W at Exit 393. 01/16/19
Exit 392 loops away from I-40 east to U.S. 11W (Rutledge Pike) a half mile ahead of Interstate 640. U.S. 11 partitions into west and east branches 0.58 miles south of I-40. 01/16/19
Spring Hill Road spans I-40 a quarter mile from the flyover (Exit 393) for I-640 west. Omitting U.S. 25W north and incorrectly referencing a half mile for Exit 393, this overhead replaced a bridge mounted sign. 01/16/19
Two lanes leave Interstate 40 east for I-640/U.S. 25W leading west across Sharp Ridge to Fountain City and I-75/275 at Inskip. 01/16/19
East End Throwback
East South at
A diagrammatic sign was previously affixed to the high level overpass for Buffat Mill Road one mile ahead of I-40. This assembly was subsequently replaced with a sign bridge. Photo by Carter Buchanan (05/01/05).
I-640/U.S. 25W span U.S. 11W (Rutledge Pike) leading into the exchange with Interstate 40. Photo by Carter Buchanan (05/01/05).
U.S. 25W joins I-40 east to U.S. 11E/70 (Asheville Highway) at the succeeding exit. Photo by Carter Buchanan (05/01/05).
West North at
Replaced guide sign for I-640 west at the U.S. 25W entrance ramp from Asheville Highway. Photo by Carter Buchanan (05/01/05).
I-40 crosses over Chilhowee Drive ahead of the separation with I-640 west / U.S. 25W north. Photos by Carter Buchanan (05/01/05).
East at
The overhead for I-640 by the gore point for Exit 393 was replaced by 2017. 11/08/09
West End – Marble City, Knoxville, Tennessee
South West at
I-75/640 head south from SR 62 (Western Avenue) and the West Haven community one mile to Interstate 40. 11/08/09
Passing west of Richmond Hill, the Knoxville bypass advances south 0.6 miles to the ramp split for I-40 east to Downtown and west to Farragut. 11/08/09
SR 169 (Middlebrook Pike) spans I-75/640 just north of I-40 by the West View neighborhood. 11/08/09
Interstate 640 concludes as I-75 southbound merges with I-40 west. I-40 travels 166 miles from Knoxville to Nashville; I-75 runs southwest 99 miles to Chattanooga. 11/08/09
East North at
I-40/75 expand to ten lanes east between Papermill Road and their separation at Exit 385. 01/16/19
0.75 miles out from the directional T interchange (Exit 385) with the Knoxville bypass (I-640). 01/16/19
The concurrency along I-40/75 uses the exit numbering system of Interstate 40. TDOT recorded 210,406 vehicles per day (vpd) west of I-640 in 2018. 01/16/19
I-75/640 east carries a third of the traffic (72,197 vpd in 2018) away from I-40 east around the north side of Knoxville. The remainder (150,957 vpd in 2018) continues east to the University of Tennessee and Downtown Knoxville. 01/16/19
West at
Interstate 40 converges with I-75/640 one mile west from the north end of U.S. 129 (Alcoa Highway). Photo by Carter Buchanan (06/10/17).
Interstate 40 runs between the West View and Marble City neighborhoods to Exit 385. I-75 combines with I-40 west for 17.03 miles from I-640 to Hines Valley in eastern Loudon County. Photo by Carter Buchanan (06/10/17).
Entering the directional T interchange (Exit 385) with I-640 east / I-75 north along Interstate 40 westbound. Photo by Carter Buchanan (06/10/17).
Sources:
- “TDOT says spring 2019 for Broadway/I-640 interchange completion.” Knox TN Today, July 16, 2018.
Page updated July 1, 2021
