(I-270) makes up a large portion of the outer belt freeway
in the St. Louis, Missouri
metropolitan area. The counterclockwise terminus of I-270 is at the junction with Interstate 55
in Mehlville, Missouri
; the clockwise terminus of the freeway is at the junction with I-55 and I-70 north of Troy, Illinois
. The entire stretch of I-270 is .
Interstate 270 between Interstate 70
and Interstate 55
was formerly designated Interstate 244, a Western bypass of St. Louis, Missouri
. It was originally proposed by Missouri as Interstate 144
, but the road was a beltway (or part of one), so the AASHTO
assigned it the number "244". By the late 1970s, the entire beltway (including today I-255) was integrated as a part of "270" for consistency. However, the politicians in Illinois started planning their supplemental freeway system in the mid 1970s and somehow a 5 mile section of "Corridor 413" was included into the Interstate Highway System in April 1978. This caused a potential place of confusion in Pontoon Beach, Illinois where I-270 would had intersected itself, and eventually IDOT decided on the 255 numbering in 1980 (but not before considering renumbering a 8 mile section to I-870).
The section of I-270 on the Missouri side was completed by June 1964, while the section that was I-244 was completed by November 1968. by Peter deLeon and John Enns,... Read More