(From research in Northwestern Universities Transportation Library)
* The Draft EIS for the US 61 corridor between I-80 and downtown Davenport notes that the Iowa DOT selected the one-way pair alternative over a western or eastern freeway alternative in December of 1975.
* The EIS for I-380 in Waterloo had the Waterloo - Cedar Falls area freeway network being a triangle with I-380 being the diagonal, US 20 being the base, and a freeway in the IA 58 corridor being the vertical post.
* According to the EIS's for the US 61 freeway/expressway in Dubuque, there were never any plans for a fully directional interchange or cloverleaf where US 61 would cross US 20. In addition, it seems the main route for US 20 and US 61 was to be a south and eastern bypass that crossed the Mississippi south of Dubuque. There was also an expressway under consideration for US 52 north of US 61 that stalled out before the EIS was started.