No argument there, but did I understand your earlier point correctly that all 18 large suburbs of Los Angeles are all so significant that we need not set Los Angeles itself apart from any of them? My contention was that, looking at the big picture, only some of them warrant that special treatment, because a city of 10,000 or 80,000 or even 100,000 isn’t necessarily very remarkable in Southern California. Nor is a city of 2,000 in eastern Colorado, even if it’s the only sign of civilization for miles around. If we want a thoughtful, deliberate classification system, it should be based on the norm, not the extremes.
At the time, some of the folks involved with highway reclassification sought to use place=city cities as the nodes in the trunk network. Sooner or later, folks involved with place reclassification would seek to use highway=trunk roads as the edges in the city network. It all strikes me as a grand exercise in circular logic. Imagine having to explain these decisions to a newbie who wants to reclassify something more naïvely but can’t because of these criteria. How do these criteria not come across as a sort of bureaucratic runaround?
It was an April Fool’s in-joke for the roadgeek community, perpetrated on their fork of OSM Americana. It referred to the choice of Limon as a control city along I-70 instead of the far more recognizable Denver. Some people get worked up about illogical control cities. As it happens, Limon is listed as one of Colorado’s trunk cities because of the long-distance highways that converge there.
What counts as federal recognition? The federal government’s official gazetteer, GNIS, includes extensive coverage of places of all sorts in several feature classes. The Populated Place class includes incorporated cities, neighborhoods, and unincorporated communities alike, as well as more questionable entries like shopping centers and mobile home parks. The Civil class covers any political division, such as a county or incorporated city. The Census class covers CDPs and the like. There isn’t a strict 1:1 mapping between Populated Place and Civil, nor between Populated Place and Census.
All three classes are federally recognized in the sense that the federal government acknowledges their existence, location, and name. GNIS records a point geometry for a Populated Place wherever a map would label it, and for a Civil or Census feature at its geographic centroid. The GNIS import included the Populated Place class, but it excluded the Civil or Census classes in favor of TIGER boundaries. It classified each Populated Place as village, town, or city solely based on its population estimate in the 2006 American Community Survey. Features that lacked a population estimate, such as mobile home parks, were classified as hamlet.
I hope it’s clear from the explanation above that any node you’re referring to is not a CDP. It’s either a populated place that is associated with a CDP (possibly by coincidence) or perhaps a centroid of a CDP that someone mapped erroneously and needs to be deleted. So I’m going to assume you’re asking about an unincorporated populated place rather than a CDP.
Just as with highway classification, it can be useful to distinguish between urban and rural areas: neighborhood, quarter, and suburb establish an urban hierarchy within a town or city, while hamlet and village establish a rural or suburban hierarchy. This urban/non-urban divide can be located at the city limits, or it can be somewhere else if the city has developed without regard for population density. If you’re ever in doubt as to whether a place is urban or non-urban, check whether it has an associated urban area and look it up on the Urban Areas Wall Map or Census Bureau Maps.
While I think factors such as amenities could be useful on the margins, place classification needs to be based on something less squishy, just to save ourselves a lot of ongoing headaches. I favor using the CBSA system as a starting point, because the OMB has already gone through the trouble of gathering and weighing demographic and economic factors. Just not the principal city designation, because it’s too rigid and places the cutoff far below where we need it to be.