High Quality Content by WIKIPEDIA articles! Interstate 44 (I-44) is a major highway in the central United States. Its western terminus is in Wichita Falls, Texas at a concurrency with US 277, US 281 and US 287; its eastern terminus is at the Illinois state line on the Poplar Street Bridge over the Mississippi River in St. Louis, Missouri at a concurrency with Interstate 55, Interstate 64, Interstate 70, and US 40 (as per the Federal Highway Administration ). I-44 is one of five interstates built to bypass U.S. Route 66; this highway covers the section between St. Louis and Oklahoma City. Virtually the entire length of the I-44 east of Springfield, Missouri was once US 66, which was upgraded from two to four lanes from 1949 to 1955. The section of I-44 west of Springfield was built farther south than US 66 in order to connect Missouri`s section with the already completed Will Rogers Turnpike, which Oklahoma wished to carry their part of I-44.