[Talk-us] Another road classification disagreement (this time with HFCS in Kansas)

[Minh Nguyen]

On 2015-09-06 01:24, Toby Murray wrote:
> This user has also upgraded a lot of unpaved county roads in eastern
> Kansas to secondary because of HFCS which also strikes me as wrong.
> You can clearly see where he has done this at zoom level 9 [6].

When I started mapping in San Jose, CA, after years of mapping in 
Cincinnati, I encountered similar problems with highway classifications. 
There were `highway=secondary` ways that, in reality, are tree-lined 
residential roads with 25 mph speed limits, Child at Play signs, and 
unsignalized crosswalks. Presumably that's because they're designated 
"major collectors" in HFCS. Residents along those streets would probably 
disagree.

Parts of downtown San Francisco and downtown Houston consist entirely of 
`highway=primary` ways with a few `highway=service`s sprinkled in. That 
kind of classification doesn't seem incredibly useful for routing, and 
it makes it more difficult to establish a visual hierarchy when styling 
a map.

In the Cincinnati area, we reserved `secondary` for good cross-town 
roads, for consistency with `secondary` state routes in rural areas. We 
demoted a grand boulevard (Central Pky., an HFCS "principal arterial" 
that's part of three U.S. routes) from `primary` to `secondary`, because 
a nearby Interstate has long obsoleted it for cross-town travel.

As I recently argued in a diary entry [1], high road classifications, 
along with umbrella landuse areas, mean that potential contributors 
won't see a blank slate where they probably should (since there may be 
little other than streets). Can we tone down these cities a bit? I think 
it would help the project.

I've come to the same conclusion as NE2 [2] that we should classify 
roads "from scratch" on a case-by-case basis and only consider systems 
like HFCS as a hint, just as we treated the TIGER import's 
classifications as a starting point. We have enough information before 
us, including aerial imagery and the overall road topology, to 
contradict HFCS when necessary.

[1] <http://www.openstreetmap.org/user/Minh%20Nguyen/diary/35646>
[2] <http://wiki.openstreetmap.org/wiki/User:NE2/classification_FAQ>

-- 
minh at nguyen.cincinnati.oh.us