Interstate 465 (I-465), also known as the USS Indianapolis Memorial Highway, is the beltway circling Indianapolis, Indiana, United States. It is roughly rectangular in shape and has a perimeter of approximately . It lies almost completely within the boundaries of Marion County, except for two short sections on the north leg in Boone and Hamilton counties. It intersects with I-65, I-69, I-70, and I-74 and provides additional access to I-65 via I-865. Route description All U.S. and state highways that formerly were routed through the central part of Indianapolis are now routed concurrently with I-465. Only I-65 and I-70 run through Downtown Indianapolis. The affected highways are: I-74, running counterclockwise from exit 16 to exit 49 US 31, running counterclockwise from exit 2 to exit 31 US 36, running counterclockwise from exit 13 to exit 42 US 40, running counterclockwise from exit 12 to exit 46 US 52, running clockwise from exit 25 to exit 47 US 421, running counterclockwise from exit 49 to exit 27 SR 37, running counterclockwise from exit 4 to exit 37 SR 67, running counterclockwise from exit 8 to exit 42 In addition, , the I-69 extension will run counterclockwise from future exit 5 to exit 37. When the interchange opens, it is expected the SR 37 designation will be removed from I-465 as well as I-69. An approximately section between exits 46 and 47 carries eight routes: I-465, US 31, US 36, US 40, US 52, US 421, SR 37, and SR 67, the largest concurrency in the U.S. In most cases, route markers other than I-74's are not posted along I-465 itself; rather, signs on the entrance ramps direct traffic traveling a particular route to follow I-465 to a specific exit to continue on that route. History Planning and alignment selection A beltway for Indianapolis was part of the original plan of the Interstate Highway System in 1955. The general alignment was to be either on or adjacent to the now-defunct SR 100, which, by then, had only two completed legs—on the north side, along 86th Street west of the White River and 82nd Street east of the river, and on the east side, along Shadeland Avenue. On the city's west side, an alignment corridor paralleling High School Road was preferred, and, on the south side, one between Hanna Avenue and Thompson Road had been proposed. Development along 86th Street made its use