[Talk-us] US Trunk road tagging

[Minh Nguyen]

Vào lúc 14:20 2021-05-05, Minh Nguyen đã viết:
> I don't think these counterexamples detract all that much from your 
> general point about NHS (or at least Other Principal Arterials) being a 
> decent potential starting point for trunk classification, assuming we're 
> OK with opening trunk up to non-expressways. But it seems like there 
> would still be some need for case-by-case exceptions. Each exception 
> would undermine the idea that NHS is the final arbiter of trunk 
> classification and thus the solution to road classification edit wars.

I think Other Principal Arterials is far too broad for highway=trunk in 
heavily built-up areas, such as the San José metropolitan area. [1] 
Intermodal corridors aren't really a problem here -- the only one is a 
street leading to an abandoned Greyhound station. But Other Principal 
Arterials includes every street we've tagged highway=primary and some 
highway=secondary as well. (It also includes some freeways, but we 
already made an exception for them.)

Coming from the Midwest, I already felt we were severely overclassifying 
roads in the Bay Area, but at least the current tagging reflects the 
built-up, car-centric environment here and distinguishes the county 
expressway system from ordinary surface streets. As much as I appreciate 
the expressway=yes tag, I think it's a bit extreme to conflate county 
expressways like Lawrence Expressway [2] and San Tomas Expressway [3] 
with conventional crosstown streets like The Alameda [4] or North 1st 
Street [5].

Seeing the situation in San José gives me pause. We may not want to rush 
headlong into a one-size-fits-all approach if it performs so poorly in 
major cities, even if it performs well in areas with less sprawl. The 
principles behind FHWA functional classifications are rigorous and 
sound, but I still don't see a straightforward way to map all these 
specific classes one-for-one to highway=* values.

[1] 
https://www.fhwa.dot.gov/planning/national_highway_system/nhs_maps/california/san_jose_ca.pdf
[2] https://www.aaroads.com/ca/g000/cr-g002_nb_at_i-280_01.jpg
[3] https://www.mapillary.com/map/im/D2uGIQlqIL1UsU17IE-Egw
[4] https://commons.wikimedia.org/wiki/File:The_Alameda,_San_Jose_0524.jpg
[5] 
https://commons.wikimedia.org/wiki/File:North_1st_Street_trench_1623_02.JPG

-- 
minh at nguyen.cincinnati.oh.us