In Iowa, Interstate 80 (I-80) enters at the Missouri River in Council Bluffs, extends east through the southern Iowa drift plain, passes around Des Moines and through Iowa City, and crosses into Illinois at the Mississippi River near Le Claire. I-80 is an American transcontinental Interstate Highway stretching from San Francisco, California, to Teaneck, New Jersey. Before the Interstate was built, US Route 6 was the busiest highway in Iowa. In the early 1950s, a turnpike along the US 6 corridor was slated to be the first modern four-lane highway in the state, but those plans were shelved when the Interstate Highway System was created in 1956. The first section of I-80 opened in 1958 in the western suburbs of Des Moines, and new sections of the Interstate opened up regularly over the next twelve years. The final segment in Iowa, the Missouri River bridge to Omaha, Nebraska, opened in 1972. About one-third of Iowa's population lives along the I-80 corridor, most of which runs through farmland. (Full article...)