The four-lane portion of US 71 between Spencer and Milford has always been a little out of place. There’s no other significant stretch of four-lane around it until I-90 to the north, more recently IA 60 to the west and, soon, US 20 to the south.
On the north side of Spencer, US 71 and 18 join/split. Construction in the area has made it particularly accident-prone. It’s been bad enough that the DOT agreed to move the speed limit down to 45 from 55 and set up message boards.
KTIV has a news story about it.