North of I - 80 , US 71 passes through Carroll , where it intersects U.S. Route 30 .
North of I - 80 , US 71 intersects and overlaps U.S. Route 20 at Sac City and U.S. Route 18 through Spencer .
North of I - 80 , US 71 passes through Carroll , where it intersects U.S. Route 30 , and intersects and overlaps U.S. Route 20 at Sac City and U.S. Route 18 through Spencer .