 In the 1960 – 1970s , Iowa DOT started to build freeway segments along US 30 . In 1965 , it was straightened and rerouted to the south of Ogden and Boone along an eleven @-@ mile ( 18 km ) , four @-@ lane stretch of road . By the end of the 1960s , both of the alternate routes had been turned over to local jurisdictions . The western route became Iowa 183 , and the eastern route reverted to Iowa 136 . By 1973 , that new stretch of road had been extended fourteen miles ( 23 km ) along a four @-@ lane bypass around Ames . The old alignment became Iowa 930 . In eastern Iowa , a new , twenty @-@ mile @-@ long ( 32 km ) freeway connected DeWitt and Clinton by 1976 . By 1985 , the bypass of Cedar Rapids had been completed from 16th Avenue SW to Iowa 13 near Bertram . The bypass was extended five miles ( 8 km ) further west in 1989 . Between 1996 and 2000 , an $ 8 @.@ 2 @-@ million extension ( equivalent to $ 12 @.@ 4 million in 2016 dollars ) was built to connect the bypass to the western intersection of US 218 . 
