September 7, 2006: IA 128 in Clayton County is an orphan segment of IA 56 created in November 1924.
In the 1920 highway system, only one non-spur route (IA 29 in Plymouth County) had an endpoint that was not in a community. This created a lot of redundancies. On November 3, 1924, and then also on January 6, 1925, the IHC took a knife to these. At the time, the markers were painted on poles, so the real-world efficacy of what I call the “Great Truncation” may be debatable. It did, however, set a new standard.
Despite there being more than a dozen changes to route termini, only two new numbers were needed to cover orphaned segments, and both are around today.
IA 39 (I) had around half its route cut. It had started in Mondamin, rather than to the southeast where the route met IA 12, went to join the Lincoln Highway at Logan, used the Harrison County stairsteps, then went east to Harlan.
The route between IA 12 and Logan, which had a pronounced arc through Magnolia, was cut from 39 and became IA 127. The rest of 39 got cut in half again at Portsmouth when IA 64’s route was changed in 1959. In the Great Renumbering, it became the westernmost part of a new IA 44 running all the way to Grimes.
IA 56, on the other side of the state, lost its connection to Guttenberg. It was cut to the corridor we know today, connecting two county seats but not touching any other town. The bottom leg of a triangle formed with IA 13 and then-IA 20 (now US 52) turned into IA 128 in the heart of Clayton County, passing through only the unincorporated village of Clayton Center.
IA 101 was also approximately cut in half, and contained to Benton County, but it retained concrete in the Cedar River bottoms that by 1924 was already more than a decade old. That concrete was lost in later route modifications, and the number itself was dropped in 1984 when I-380 made a long stretch of IA 150 redundant and the DOT had to figure out what to do with the latter.
