Interstate 275 in Knoxville was constructed in 1958 as part of the I-75 mainline through Knoxville. Changes to I-75 were made ahead of the December 1980 scheduled opening for the western leg of I-640 between I-40/75 near Marble City and I-75/U.S. 25W by Inskip. The Tennessee Department of Transportation (TDOT) requested approval from the American Association of State Highway and Transportation Officials (AASHTO) to renumber I-75 from I-40 in the Downtown area to I-640 north of Sharp Ridge as I-275 and reroute I-75 along the western leg of I-640. The application sent December 6, 1979 cited the following reasons:
1. By routing I-75 along the western leg of I-640 rather than its existing route through town, travel distance can be reduced by 1.79 miles, a substantial savings in travel time and fuel consumption.
2. At the present time through traffic on I-75 must traverse nine interchanges and one major directional interchange along its route through town. The proposed routing along I-640 includes only two interchanges. With less merging and diverging traffic conditions, the routing along I-640 would be desirable from a safety standpoint.
3. With this change, elimination of overlapping major Interstate routes, (I-40, I-75) would result in the downtown Knoxville area.
The Federal Highway Administration (FHWA) and TDOT came to an agreement following communications between November 1979 and January 1980. The I-75/640 overlap would be attributed solely to I-75’s mileage, and I-275 established as proposed. The changes were approved by AASHTO on June 24, 1980. The realignment of I-75 onto the bypass preceded reconstruction of I-40 east from Marble City to I-275 and the 1982 World’s Fair held in Knoxville.
U.S. 25W previously overlapped with I-75 north from I-40 outside Downtown Knoxville to the exchange with I-640 and Clinton Highway. When I-640 was completed to the northeast, U.S. 25W was rerouted from U.S. 11/70 (Magnolia Avenue) west to I-40 and from I-75 north. Central Street paralleling I-275 to the east is the original alignment of U.S. 25W.
A $20 million reconstruction project along Interstate 275 took place between December 1, 2006 and January 26, 2008. Work expanded portions of the freeway to six lanes and reconfigured three interchanges from cloverleaves to diamonds. The interchange modifications increased the ingress and egress movements from 300 feet to 1,200 feet.1 This upgrade was completed ahead of the “Smartfix40” widening of Interstate 40 east from Downtown Knoxville.