No other objects or tags were touched.

Edit: No it's not.

See changeset/145394324.

In this location, a single-letter (or even a double-letter) supplemental route would not be used for the purpose. If anything, an unsigned spur of 179 would be used.

On June 15, 2023, I added ref and relation for a supposed MO P in Wooldridge apparently based on Bing StreetSide. I can't verify that now, and I do not remember why I added it.

Also, being a designated county road might make it unclassified rather than track? Something for the future

to the east, not north*

It runs parallel to HH to the north, so HH does actually need to be adjusted still.

Typo: Route*

I write that a lot when I type fast.

I'm no longer un-naming singly-designated segments of highway, so I change the name of those ways from "MO 30" to "State Highway 30".

Turns out GPS validated Bing imagery, and the bridges were actually just wrong.

I also used GPS data on this one to verify the bridge since it was offset a bit.

This is in St. Clair County, Missouri.

I also added a missing concurrency between Y and 23.

I also reworked an intersection just north of Missouri State Fair, and I added footways in the process.

I also added a missing concurrency between D and Y just south of Whiteman Air Force Base.

I extended the relation west to Bowmansville, as it was incomplete.

Large bbox due to U.S. 36 relation being touched

I also added ref: to the stretch of road under I-70 here. Previously it was mapped using ref:forward and ref:backward, and I understand why, but data consumers want the route designation in the plain ref tag afaict.

This bumps into a semantic point about where specifically a route begins and ends. Route signs are great until they're not, and sometimes they're really not. The MoDOT Transportation Management Center opines that there's technically a concurrency between J and O under the overpass, though, which connects each supplemental route to the opposing interstate ramp, so that's what I'm going with.

I am open to suggestions here about the route termini, but I think a single coherent "ref" tag is still important in 2023/4.

I also added stop signs and the bridge deck with MoDOT reference code.

I also added footways on and near that overpass.