the same time. Work on the segment between I-75/I-275/US 25W and US 441 began in October 1968 and was completed on December 15, 1970. The remainder of I-640 was initially delayed by disputes over its final alignment and disagreements between the city of Knoxville and the state over the improvement of nearby surface streets. In addition, new requirements imposed by the National Environmental Policy Act (NEPA) of 1969 required that an environmental impact statement (EIS) be prepared for the remaining segments. Environmental studies took place between 1973 and 1978, with the Federal Highway Administration (FHWA) approving the EIS for the western leg in November 1975 and the EIS for the eastern leg in March 1978. Construction of these sections was then funded as part of a $250 million (equivalent to $ in ) multiphase improvement project on multiple roads in the Knoxville vicinity that was conducted in preparation for the 1982 World's Fair. Construction on the section between I-40/I-75 and I-75/I-275/US 25W began in October 1977, and work to modify the Sharp's Gap Interchange, which included construction of two new flyover ramps, began in August 1978. This section opened to traffic on December 23, 1980. At this time, I-75 was rerouted onto this section, and the part of I-75 between I-640 and I-40 in downtown Knoxville was renumbered I-275. This was done in an effort to divert through traffic on I-75 away from the World's Fair. Work on the final section, located between US 441 and the eastern terminus with I-40, began in July 1979 and was opened to traffic on December 21, 1981. Final signage, lighting, and landscaping work was completed in April 1982, and the flyover ramp from I-40 eastbound onto I-640 at the eastern terminus opened on July 1, 1983. Then-Governor Lamar Alexander officially opened both sections by leading a walk along their entire lengths dressed in his red plaid shirt that he famously wore during both of his campaigns for governor. I-640 was the last interstate highway to be completed from the original 1956 allocation for the East Tennessee Grand Division. Later history A new exit ramp from I-640 eastbound to Gap Road was constructed just east of the Sharp's Gap Interchange between December 18, 1985, and August 6, 1986, providing direct access to US 25W from the eastbound lanes for the first time. The section of I-640 between the Sharp's Gap Interchange and US 441