 US 30 enters Benton County nine miles ( 14 km ) north of Belle Plaine at an intersection with Iowa 21 . It continues east along a section line , passing the communities of Keystone , Van Horne , and Blairstown . Three and a half miles ( 5 @.@ 6 km ) southwest of Newhall , or four and a quarter miles ( 6 @.@ 8 km ) southeast of Van Horne , it meets US 218 and becomes a four @-@ lane road . US 30 and US 218 travel together due east towards Cedar Rapids , passing Norway and Atkins . 
