There are three Interstate highways designated Interstate 240 in the US.

North Carolina

Oklahoma

In Oklahoma, I-240 runs 16.22 miles west from Interstate 40 to Interstate 44 in southern Oklahoma City. After its terminus in SW Oklahoma City, I-240 becomes Interstate 44 and Airport Road toward Will Rogers World Airport.

The part between I-35 and current I-44 was already done in 1965. A loop along current I-44 up to OK 66, then east to I-35 again, was a planned extension of I-240, for a total of 31.76 miles but was rejected in favour of the current designation.

Major destinations along the route include Crossroads Mall , the suburb of Moore, and the heavily populated Southside of Oklahoma City.

Tennessee

Running 19.27 miles, this Interstate highway loops southward from Interstate 40 in east Memphis, then turning west at TN 385 (Bill Morris Parkway). At I-55, the highway turns north and runs through midtown to end at I-40.

I-240 was first planned circa 1955, but it was to have been a 30.8 mile beltway to completely encircle midtown Memphis, with the exception of the segment between Interstates 40 and 55, which was proposed as I-255. Later, that number was decommisioned in favor of I-240 running in a full loop, with I-40 running from Downtown to east Memphis. However, in 1957 citizens collected 10,000 signitures protesting the route, which cut through Overton Park in midtown. The controversy lasted until the 1970's, when the Supreme Court ruled that the Overton Park route be cancelled, shifting I-40 onto the northern leg of I-240. The interstates were duplexed around the northern bypass of Memphis for many years, but I-240 was later removed from the northern leg for reasons of redundancy.

I-240 has seen much reconstruction over the past decade, as area growth has demanded increased capacity. Both interchanges with I-40 are currently under reconstruction due to the amount of traffic taking I-40 through Memphis.

Source: 3 Digit Interstates at www.kurumi.com