[Imports-us] Spartanburg County SC road centerlines import

Mike N niceman at att.net
Mon Oct 22 12:39:18 UTC 2018


Thank you for your comments.  Answers inline.

On 10/22/2018 5:00 AM, Rory McCann wrote:
> On 22/10/2018 05:20, Mike N wrote:
>> This is a proposed import of road centerlines for Spartanburg County 
>> SC, based on county GIS data.   This will include a systematic review 
>> of all roads in the county and qualify to remove tiger:reviewed tags.
>>
>> https://wiki.openstreetmap.org/wiki/Spartanburg_county_road_center_line_import 
> 
> 
> A roads import! 🙂
> 
> There's a few lanes that are weird. lanes=7 for a 6 lane road. It's 
> weird that some roads have lanes on some parts, not all (e.g. "Hollywood 
> Street"). Maybe try to make it consistant? JOSM validator has found a 
> handful of topology errors. There's ~100 examples of roads that aren't 
> connected properly (nodes on top of each other, but not connected).
> 
> You seem to be defaulting to "highway=residential" a lot (e.g. if you 
> dohn;t know another, or turning 'Gravel' into 'highway=residential 
> surface=gravel'). I don't know a lot about tagging in the USA, but isn't 
> there (wasn't there) some problem with the TIGER data using residential 
> too much?

   The 'lanes' and highway type were experimental to see what useful 
information could be mined from the source data.   I agree that they are 
all but useless for OSM's purpose.  95% of the work will be checking for 
geometric alignment and name from the background image layer in the 
editor.   For example there have been many projects where sharp 
intersections have been realigned for safety to create right angles. 
And streets have been renamed for E911 purposes.

    The one case where I see direct access to converted data is a new 
residential subdivision - where a new group of roads would be copied 
from the reference data and connected to existing data.   Those would 
nearly all be residential.  So I didn't take the time to go back and 
remove lane attributes from the raw data.

    Defaulting to residential was not totally wrong for this county in 
the same way it was wrong out west.  The most likely mismatch would be a 
new unclassified road into an industrial area - but those will likely be 
single roads, and thus be as easy to hand trace and assign the correct 
classification as to copy from the reference layer.

> Can you link to your discussion with the local community, how/where did 
> that happen?

   This was mostly verbal discussion with another community member, as 
well as one of the meetups at 
https://www.meetup.com/Open-Street-Map-upstate/ , and using some of the 
ideas presented by Clifford Snow in his "Discover Rural America" 
presentation at https://www.youtube.com/watch?v=EoX2Q2aJXQE&t=1211s .

> The link the tasking manager project doesn't work.

    Corrected.

> I'm a little unclear about one big question: What are you doing with the 
> existing data in OSM? Existing OSM data seems to have nearly identical 
> locations to this new data. You're just going to update existing OSM 
> data? Do you know how much existing OSM data needs to be updated?

   All existing data will be reviewed.   Most of it will add the surface 
attribute and lanes if visible from imagery and remove the 
tiger:reviewed attribute.   So nearly everything will be modified.

    Stepping back to the big picture - although many hours have been 
spent improving the road network in that county, OSM is the last source 
I would use when planning a trip to an unfamiliar part of the county. 
There have been other US projects in which a group would go into a "fast 
growing region" and review all roads, adding surface and lane attributes 
to improve navigation.   The end goal of this project is similar.   When 
combined with some additional planned work such as address points, OSM 
will be suitable as the primary reference source when planning a trip 
through that county.



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