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3-digit ("branch") US route numbering curiosities and violations

I consider the numbers below to be major violations, because 1.) the routes have never come anywhere close to their implied "parent", nor to any of their implied "siblings"; and 2.) because logical alternatives were available, which would've fit within the numbering guidelines.
US 101 Some people don't consider this number to be a violation. In a way, it kind of makes sense to have US 1 running along the East Coast, and US 101 on the West Coast. But when viewed in the context of all other US routes, the number implies a branch of US 1 - and in that sense this number is a major violation. I think the route should've been assigned US 99 or US x99.
US 163 I can't imagine what AASHTO was thinking when they assigned this number, but I will admit there wasn't an easy solution. Looking at a modern map of the area, you'd think US x91 would've been a good choice... but keep in mind that when this route was commissioned in the early 1970s, US 191 hadn't yet been extended through eastern Utah. So the original US 163 went all the way up to Crescent Jct, and connected only with even-numbered routes: US 160 at its south end, US 666 in the middle, and US 6/50 on the north. Given that, I guess I would've narrowed it down to either US x60 (even though it was a north/south route) or US x89 (even though it didn't connect with US 89). Neither of those is perfect either, but US 163? Where'd that come from?? Anyway, now that it does connect with US 191, I think it should be changed to US x91. Maybe "391", since there's already a SR 291 in UT (although it's a very minor, unsigned route). That would be interesting, too, since "391" is kind of "163" turned upside down... you can click here to view a map showing US 163 in that context.

(The "4xx series" routes below were commissioned in the 1980s and 1990s. At least two of them are along "high-priority corridors" and/or a possible future interstate route. But that doesn't excuse the fact that they were assigned numbers that are drastically out of sync with the rest of the system. The links below go to maps [averaging about 100k in size] that show these routes alongside the indicated route families.)

US 400 Wouldn't one of these options have made more sense?
x50 (its westernmost 135 miles are co-signed with US 50)
x54 (it's co-signed with US 54 for 143 miles through KS)
x66 (it connects with US 166, and it's supposedly the future I-66 corridor)
US 412 What was wrong with these possibilties?
x56 (its westernmost 135 miles are co-signed with US 56)
x60 (it's co-signed briefly with US 60 in OK)
x62 (it's co-signed with US 62 through much of AR)
x64 (it's co-signed with US 64 through much of OK)
x70 (it meets US 70 in TN and US 270 in OK)
US 425 Originally this route connected to US 65 on one end, and US 165 on the other. So why not US 265? [map] Now that US 425 has been extended south to Natchez, I think the entire thing should be renumbered as US 65. The current segment of US 65 between Pine Bluff AR and Clayton LA could be renumbered US 265... and then the number "425" would be nothing but an infamous historical footnote.
I consider the numbers below to be "technical violations": these routes never actually connected with their implied "parent", but they were close enough that I believe their numbers were acceptable nonetheless.
US 104 Maybe x20 would've been a better choice. But, in its defense, it was on roughly the same latitude as US 4 [map].
US 121 While it does connect with the historic US 21 corridor [map], this route was created some 30 years after US 21 had been decommissioned in that area. US x19 would've made the most sense, and US x23 would've worked better, too.
US 164 [II] Today US 64 does connect with the former route of US 164 (at Teec Nos Pos AZ). But during the brief period when 164 existed, the west end of US 64 was in Santa Fe NM [map]. US 164 connected with US 66 and US 89 on one end, and US 666 and US 160 on the other... so US x66 probably would've been a better choice. (US 766? Or else US 366 [III] and US 566 were available.) On the other hand, much of the route lay along what had only recently been designated as AZ hwy. 64, so maybe the number "164" was intended to minimize confusion.
US 410 It could've been x95, x97, or x99... but it was an east-west route. Playing off US 730, it could've been US 930 (the only remaining x30 number then available). But that seems like a stretch. So I think 410 was a pretty good choice, all things considered [map].
US 830 Ran parallel to (and right across the Columbia River from) its implied parent, US 30 [map].
A handful of US routes connect(ed) with a sibling, but never their implied parent. In other words, they're "branches of branches". So I don't consider these to be numbering violations - only idiosyncrasies.
US 701 Connects with US 301 and US 501 [map].
US 309 Connected with US 209 [map].
US 411 [II] Connected with US 311 [map].
US 217 Connected with US 17-1 [map].
US 220 Connected with US 120 [map].
US 566 Connected with US 366[I] [map].
US 187 Connected with US 287 [map].
US 491 Connects with US 191 [map].
US 295 Connected with US 195 [map].
US 395 Connects with US 195 [map].
Several existing US routes no longer connect with their implied parent, but did historically. For that reason, I don't consider these to be numbering violations. In fact, some of them are interesting historical relics.
US 310 Connected to US 10 at Laurel MT [map].
US 311 Connected to US 11 at Roanoke VA [map].
US 411 Connected to US 11 at Greeneville TN [map].
US 212 Connected to US 12 at Willmar MN and Miles City MT [map].
US 219 Connected to US 19 at Princeton WV [map].
US 138 Connected to US 38 at Sterling CO [map].
US 641 Connected to US 41 at Evansville IN [map].
US 158 Connected to US 58 at Franklin VA [map].
US 166 Connected to US 66 at Joplin MO [map].
US 266 Connected to US 66 at Oklahoma City OK [map].
US 276 Connected to US 76 at Laurens SC [map].
US 277 Connected to US 77 at Oklahoma City OK [map].
US 180 Connected to US 80 at Weatherford TX [map].
US 380 Connected to US 80 at Cisco TX [map].
US 181 Connected to US 81 at San Antonio TX [map].
US 281 Connected to US 81 at San Antonio TX [map].
US 183 Connected to US 83 at Vivian SD and Junction TX [map].
US 283 Connected to US 83 at Junction TX [map].
US 191 Connected to US 91 at Idaho Falls ID and Brigham City UT [map].
US 199 Connected to US 99 at Grants Pass OR [map].