[Talk-us] Rural US: Correcting Original TIGER Imported Ways
clifford at snowandsnow.us
Mon Feb 12 21:52:56 UTC 2018
On Mon, Feb 12, 2018 at 9:55 AM, Kevin Broderick <ktb at kevinbroderick.com>
> Please, please, please don't convert rural roads to tracks based on
> imagery alone unless it's incredibly clear (and that would exclude anything
> with forest cover).
> While many of them should definitely be unclassified, not residential,
> downgrading the main rural routes to tracks doesn't match local usage nor
> the functional topology of the road network in such places. There are a lot
> of USFS and BLM roads around here that are the only way to access
> significant areas, that commonly see normal passenger-car traffic and that
> can be traveled at reasonable speed in a sedan (or at 30+ MPH with a little
> ground clearance and driving skill),. Having these differentiated from true
> tracks (where even a stock 4x4 is likely going to be operating at 15 MPH or
> less) is incredibly helpful for routing and visual use of the map, and it's
> a lot easier to recognize what I'd call "areas of questionable data" when
> they haven't been aggressively armchair-mapped. Also, the smoothness key is
> really helpful for tracks and impossible to map from orthoimagery.
I live next door to forested land. I can see forest service roads from my
house, especially after a clear cut operation. Most are their to aid in
harvesting operations. Once the work is done, the road is unmaintained.
Washington State, particularly western Washington State are full of these
artifacts from the TIGER import. These ways have long since disappeared
from Census TIGER data. If they belong in OSM, someone should map them.
Let's not leave in these potentially dangerous ways only because they might
be real. There are a couple of good sources for better data, first the
2017 TIGER layer can help identify if the road is in someone's database. If
its in TIGER, then I'd leave it in OSM. The US Forest Service layer is
another good source. But like Washington State's DNR data, much of it's
unknown. Of the 925,000 roads in the DNR's database, 84% are in unknown
status. Only 12% are active, and those include state highways. The rest are
abandoned, decommissioned, orphaned, close or not yet built. I did talk to
the DNR about using their data, but they cautioned me against it for the
same reason I'm trying to clean up the old TIGER data - the data is
garbage. If the state doesn't know, then I doubt the USFS is any better.
> Even with local knowledge, it's tough to look at some of the local unpaved
> roads on imagery and identify which sections are car-friendly and which
> aren't (and it's often different for different sections of the same road,
> e.g. Crooked Creek Rd. that goes from Carbon County, Wyoming into Carbon
> County, Montana in the Pryor Mountains is arguably a track where it's on
> BLM land and is definitively a good gravel road through USFS land). Most of
> the rest of the roads in the Pryors are either questionable on the track vs
> road border or very clearly tracks. Right now, many are still labeled as
> roads, which is obviously wrong, but downgrading piecemeal without being
> able to correctly classify the whole area makes it much harder to glance at
> the GPS screen and say, "OK, I need to take this with a shaker of salt,
> there's no way there are that many good roads in there"; downgrading some
> but not all would give a false impression of data precision.
How does leaving them in help?
> Yes, it's unfortunate when people decide to blindly follow their GPS or
> online mapping route without applying common sense, but it's better to have
> data that is obviously low-precision (at least to anyone used to traveling
> in such areas) instead of giving the false impression of higher precision
> than is actually present. It's also misleading if the whole road is marked
> as a track when several (or more) miles are maintained gravel and it then
> turns into a 4x4 track, as someone can easily start driving up the
> maintained gravel, think "Oh, this is what they mean by track—I can drive
> this, no problem" and then end up way up an effective dead end that
> connects through only on a dirt bike, ATV, or 4x4.
> I'd agree 100% that it would be great to have more mappers in rural areas,
> and I wish I had the time to deal with the data s***show in some of the
> more-remote places around here. I've updated a few things that I've driven
> and could remember how good (or bad) the road was, but unless I remember to
> take georeferenced photos or notes, it can be really hard to remember what
> was passenger-car friendly vs. what was something that I'd prefer to ride
> along in someone else's Subaru for. The problem isn't unique to OSM; none
> of the printed maps I've found are particularly great on the same roads
> (including both Delorme Gazetteers and Benchmark Atlases).
The long term fix is more mappers, especially rural, hunters, hikers,
off-road bikers, etc.
OpenStreetMap: Maps with a human touch
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