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