Hello, such short isolated segments of road such as the sections of Route 100 that you've retagged as motorways should not be tagged as motorways. Albeit arbitrary, the OSM US community usually agrees that every segment of motorway typically should have at least more than one grade-separated interchange and be multiple miles long. See here: osm.wiki/United_States/2021_Highway_Classification_Guidance#Motorway

I don't believe there's any automation involved, but rather it's that the Lyft editors usually just map without any context other than more up-to-date imagery than what we can access for free (since Lyft can afford to provide such imagery to its own employees). This occasionally results in temporary roads being mapped, roads being given incorrect tags (most commonly residential roads being mapped as service roads), and several distinct streets being mapped as one zig-zagging way rather than multiple separate ways. Their primary focus is to get the data out their as quick as possible. While fast usable data has its pros for OSM-based nav systems like Lyft uses, that leads to questionable quality control unlike a volunteering mapper not tied to strict guidelines or company contracts (like you and I) would be able to provide.

These trunk routes have been around for a while as far as I know and are definitely just leftovers from when all expressways and other "expressway-ish" arterial roads were tagged as trunk roads. Put together, Alvernon Way, Route 210, and Kino Pkwy don't really form a coherent route, especially for non-local long-haul traffic or intracity commuters. They pretty much all serve the same purposes as roads like Broadway, Speedway, or Campbell do, just at different construction standards.

Hello—what is your reasoning for restoring trunk road classification for some of the roads here?

While that is true, I wouldn't overthink the classification of such a short segment of a road that is already tagged as a primary/trunk road for the rest of its route, especially considering it's not really a dead-end stub or anything. Either tagging scheme is fine.

Considering it is still within an active construction site, connected only by other under-construction roadways, and likely does not yet have all its lane markings/other finishing touches, tagging it as an under-construction road makes more sense rather than tagging it as an implied completed road.

I'm not sure why they mapped it, but they likely were unaware that it was a temporary installation part of the F1 track.

Hello. Just to let you know, the ramp you mapped here no longer exists and was demolished a couple years ago. The interchange right here is being reworked.

What makes these changes unsubstantiated? How a road serves in the local road network can be explained by its connectivity with destinations/other roads (its usage as an arterial, collector, etc.) and traffic counts.

Yes, I think so