With my upcoming exploration of the 1920 highway system, I thought it might be a good idea to explain certain terms and concepts that will come up often. This can double for explanation of the website in general.
I’ve done a lot of research over the years, and it’s gotten me all the way up to … being labeled an unreliable source by Wikipedia.
- Iowa State Highway Commission: Created in 1904 as part of the Iowa State College of Agriculture and Mechanic Arts, and separated from the university in 1913. The commission, or “IHC” as I might write, was replaced by the Iowa Department of Transportation in 1974. Its functions related to roads are now done by the Iowa Transportation Commission. As far as I know, it is the only state agency in the country that is not headquartered in its capital city.
- The 1920 system: A network of primary highways across the state of Iowa put into use in July 1920, a year after the Primary Road Act dictated creation of such a network. This system forms the basis of all that came after. Road markers were painted onto poles, with the number inside an outline of the state of Iowa, on the week ending July 17. Iowa was the fifth state in the Midwest to do this, following Wisconsin, Michigan, Illinois, and Minnesota.
- The Great Truncation: In November 1924, with some followups in January 1925, many primary road numbers that overlapped other numbers for significant distances or were redundantly marked to end in a town instead of a rural intersection had their termini changed. The most notable byproducts of this were IA 127 and IA 128, both around today.
- The 1926 system: A statewide overhaul of the new system, brought into effect in the fall of 1926 with the creation of a national network of primary roads we call “US routes”. Primary numbers that had kinda-sorta followed the auto trails, which didn’t really begin to die out until the Great Depression, got broken up. This is when the circular shield became Iowa’s marker; it used to have “Iowa” at the top until about 1950.
- Huebinger guides: The Iowa Publishing Co., under the direction of Melchior Huebinger, put out turn-by-turn guides and maps for major early 1910s Iowa auto trails, eight of which have been digitized in the University of Iowa’s collection. (Note: Previous digital collections links appear to have 404’d at the beginning of 2020.)
- Huebinger maps: The Iowa Publishing Co. is also responsible for the large maps used for official records of county roads because, according to the very first meeting of the independent highway commission, “the Iowa Publishing Company is the only one possessing the data which the Commission would need for the preparation of county maps required to be furnished by law.” County maps from Huebinger’s Automobile and Good Road Atlas of Iowa, published in 1912, have some auto trails otherwise unknown.
- “Corridors”: Let’s say I successfully take my time machine to March 21, 1921 — the day the Iowa flag becomes our state emblem. I park my DeLorean in a shed or hide the TARDIS where it won’t be mistaken for an outhouse. I get dressed in appropriate period clothing and hang out in a courthouse square. Someone asks me, “How to I get to [other county seat] from here?” Corydon to Knoxville? Follow #14. Fort Dodge to Algona? Follow #16. Dubuque to Davenport? Follow #20. It doesn’t matter the alignment specifics, if I can give them a number or set of numbers connecting the two locations, that can be a corridor. Today’s Cedar Rapids-Iowa City corridor has three alignments used at various times by IA 11/40, US 161, US 218, and I-380.
- “Stairsteps”: East a mile, north a mile, east a mile, north a mile. Or south half a mile, west half a mile, south half a mile, etc. Any pattern in a short range that would have required multiple turns, often ironed out between 1928 and 1938.
- Spurs or stubs: A primary route that does not have one of its termini at another primary route, ending in a city or at a state park instead. I took “spur” as a variant of the term from the interstate highway system, where an odd three-digit number indicates a branch off a parent route. Official documentation, though, used “stub.” But I’m too set in my ways.
- The Great Renumbering: Iowa renumbered more than a dozen routes to create uniformity with neighboring states. Although we have traditionally used January 1, 1969, as the change date, the signs were swapped the week between Christmas and New Year’s, so it might be more accurate to say the old routes ended December 31, 1968.
- The Great Decommissioning: In 1980-81, confronted with new financial realities and population needs, the Iowa DOT offloaded many, MANY miles of spurs to county and city maintenance. This resulted in a lot of numbers being dropped from state highway logs.
- The Second Great Decommissioning: In 2003, the Iowa Legislature passed a law allowing the DOT to dump all the spurs it hadn’t gotten rid of nearly a quarter-century earlier, along with a backlog of previously important two-lane roads that had been bypassed by four-lane routes.
- The archives: One of two groups of documents:
- Iowa Highway Commission minutes on microfilm, mostly researched in 2006 and 2007. Many dates from the first half of the 20th century will be taken from these. Unless there is a primary source with additional information about when a highway was constructed or signed in the field, this is the base date.
- Construction blueprints from the Iowa DOT’s Document Portal/Highway Plans Collection. These are the files toiled over in the drafting room for decades, marking every tree, every house, every surveyor’s nail pounded into a telephone pole. They offer wonderful insights, but somehow, are often extremely bad at saying exactly when each construction project was completed. “Final approval” can come anywhere from one to five years later.
- County maps: The 1912 and 1913-14 sets available on the DOT’s Document portal are noted above. Some of them have never-would’ve-guessed insights; some have mysterious missing connections that absolutely should be there for updates made before the late 1930s, but aren’t. None of them are great at saying where inside a city limits a route went. The next sets up are from 1945 (used as tract maps for the 1950 census), 1972 (large Highway Commission book), 1997 (same), and modern PDFs.
- Newspaper articles: For those of you who didn’t do History Day, “A primary source is a piece of information about a historical event or period in which the creator of the source was an actual participant in or a contemporary of a historical moment.” News stories of the time, found through the digitized archives at Advantage Preservation, are primary sources. They, and other primary sources, might use language we wouldn’t use today. Digitized highway blueprints are a primary source, too.
- “Functional equivalent”: If, in the 1920s, someone told you to turn at such-and-such a corner of intersecting routes, where would you make the same turn today? It may not be the same geographic point, but if it’s close and serves the same purpose, a comparison can be drawn.
- Ambiguity indicators: About, around, circa, probably, -ish. Roadgeek intuition at work.
Sins of omission are due to lack of some piece of evidence or another, and will be fixed when new or clarifying information is made available. Sins of commission happen because I’m an idiot.
If there’s anything you’d like added to the list, just let me know.