May 11, 2002: South end of IA 322 in Pammel State Park. Photo by Neil Bratney.
Semi drivers making bad decisions caused a state highway to be renumbered in 1982. From the DOT’s newly online primary route archive:
The park officer at Pammel State Park has expressed concern of evident confusion of semi trucks turning south on Iowa 162 (two to three trucks per week) while apparently looking for US 169 approximately 1 ¼ miles east of Iowa 162. It is very difficult for these vehicles to turn around. Due to the inconvenience caused by the closeness of route numbers, Iowa 162 should be re-designated as Iowa 322 to eliminate this confusion.
The first two digits were doubled from “16” to “32” to clear up confusion; the last digit stayed 2 because IA 324 was already in use.
There’s one highway mystery solved, but there’s still another: Why was IA 19, a nice small number stuck as a 2-mile road to Backbone State Park, renumbered IA 410 in the late 1950s? The legal descriptions don’t shed any light on this one.