I have spent a very large amount of time cleaning up TIGER in rural
areas of Florida. I agree with others that the vast majority of
untouched TIGER ways in un-populated rural areas classified as
residential are forest roads for logging trucks at best and pure fantasy
at worst, with tons of barely grass paths all over the place. Many of
these roads are on private lands that you can't (or shouldn't) access
anyway. Spatially accuracy is often horrific. I've reviewed a decent
amount of 2017 TIGER and many areas have not been fixed. The best
secondary source of data I have found are county streets from the county
GIS departments, but those vary widely in quality. At the very least the
county data shows you where all the forest tracks, farms tracks and
imaginary TIGER streets are, because they are not there in the county
data sets. Many times, a residential street having no name is a strong
tip as well that it is not a residential street.
Kevin, I hear where you are coming from, but I think your case is
somewhat unique. Most people aren't going to look at a GPS with OSM data
in it, see a bunch of residential roads in a rural un-populated area and
think, OK, that must be unedited TIGER, but I know there's a few
navigable roads in there somewhere, I just need to find them, record
what I found and make some OSM edits. If they know the area, they are
going to think this data is junk. If they don't know the area and they
head into it they will then figure out pretty quickly the data is junk.
I agree with others that these roads should probably not be in OSM at
all - let the locals add the real roads and tracks. But we are living
with the old TIGER, and there is some potential usefulness that can come
from it. So as others have said, we are willing to leave them there,
downgrade them to track without a grade assigned for now, maybe make
some spatial corrections, delete roads that are obviously pure fantasy,
etc.
I don't think there should be any requirement to cover a certain size
area when reviewing these areas. We need to be thankful that someone has
taken the time to look at even a small area of rural areas that don't
get much attention normally at all, especially private lands.
Brian
On 2/12/2018 6:02 PM, Kevin Broderick wrote:
If you can cover an entire area (which I'd define as a swath between
the nearest state highways), I agree that downgrading to track absent
other clues is one reasonable solution. One of my key points is that
anyone who's spent a fair bit of time trying to use GPS maps (of any
origin) in poorly-mapped areas will quickly recognize an area that is
clearly an unverified TIGER import, which signals both (a) that the
data is clearly questionable and (b) that it might be an interesting
place to explore to find out if the roads do go through or not. The
questionable map data can be very useful, especially in conjunction
with other data sources, in attempting to piece together a route
through an area that lacks fully maintained roadways. If a track
doesn't actually exist, yes, then it should certainly be deleted, but
I've ridden right-of-ways that were damn near impossible to see with
leaf-on imagery and also found other routes that looked more road-like
via the same imagery impassable, so I definitely wouldn't delete
anything unless you can get there in person and look for evidence of a
roadway, perhaps one that hasn't been maintained in decades (e.g.
Class IV roads in Vermont and Class VI roads in New Hampshire).
Downgrading some ways to tracks without doing so to a whole localized
network creates the appearance of a higher level of data accuracy than
actually exists, which IMO is more likely to bite someone in the ass
than having a localized network of roads that are mislabeled. I know
it would make some of the exploring I've done via on/off-road
motorcycle more difficult.
I'd also suggest that leaving tiger:reviewed at no is appropriate if
you haven't been able to travel the road/track in question and
determine whether it is really an unclassified road or a track, so it
remains flagged for further review if someone has the time and
proximity to do so.
On Mon, Feb 12, 2018 at 3:39 PM, Martijn van Exel <[email protected]
<mailto:[email protected]>> wrote:
I am very happy to see this rekindled interest in TIGER cleanup!
Having done a fair amount of backcountry exploring, I know that
there is a wide range of road grades and aerial imagery alone is
not enough to decide how navigable a roads is for a particular
type of vehicle. Or, for that matter, what its access limitations
are. I do agree with Clifford that leaving them as poorly aligned
'residential' roads is the worst possible situation. Yes, worse
than deleting the road altogether. What I usually do is mark the
road as track without a track grade tag. This seems to me to be
the most acceptable generic solution for a remote mapper:
acknowledging that something that could potentially be navigated
by a 4 wheeled vehicle exists, without being more specific. Local
knowledge can then come to the rescue to upgrade to unclassified
if appropriate.
Another note on the MapRoulette side of things: I would very much
appreciate your feedback on the new MapRoulette version Clifford
linked to. Just email me, join #maproulette on slack, or file an
issue at https://github.com/maproulette/maproulette3/issues
<https://github.com/maproulette/maproulette3/issues>.
Martijn
On Mon, Feb 12, 2018 at 3:08 PM, Kevin Kenny
<[email protected] <mailto:[email protected]>>
wrote:
On Mon, Feb 12, 2018 at 12:55 PM, Kevin Broderick
<[email protected] <mailto:[email protected]>> wrote:
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.
Yes, yes, yes.
In the rural areas that I can travel to readily, TIGER is
downright hallucinatory (and there are few enough mappers that
cleanup has been agonizingly slow). TIGER has roads in places
where no road is, ever was, or even ever could be. (I've seen
one going up a series of cliffs totalling about 2000 feet of
ascent!) But even in 'leaves down' images, it's nearly
impossible to see the forest roads, much less trace them, and
there is definitely a wide variation in quality. Some of them
are well-compacted sand and shale, that once they've been
rolled in the spring, support driving at 30+ MPH. Others, I
wouldn't bring my Subaru on. (Although I've been on a few of
those in the ancient Ford Explorrer that the Subaru
replaced.) Some are gated, some, you simply have to decide
for yourself that they're not drivable.
The 'dirt roads' range from 'highway=path
abandoned:highway=track smoothness=impassable' to
'highway=tertiary surface=compacted smoothness=intermediate',
with no way for an armchair mapper to tell among them.
The old road maps that they used to give out at gas stations
had, on many of these roads, "inquire locally for conditions,"
which is still good advice. The signage may say, "LIMITED
PURPOSE SEASONAL-USE ROAD: No maintenance November 1-April 15"
- but in practice, they'll keep it open later in the Autumn
unless the snow comes early, and when they open it in the
spring depends on when the crews can get it clear - it could
be weeks late if there's been a bad washout or rock slide.
There's absolutely no way to tag and encode that sort of
thing. Inquire locally for conditions.
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