Author Topic: GA/TN: move location of state line on TN 68  (Read 424 times)

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Offline neroute2

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GA/TN: move location of state line on TN 68
« on: February 27, 2020, 08:18:45 pm »
I drove this today and noticed that the state line is marked on the road in blue. It seems to cross the centerline of the road between the stop line and the crosswalk. So the proper location is GA/TN http://www.openstreetmap.org/?lat=34.988163&lon=-84.370043 .

By the way, GA TN68 is about 35 feet/11 m long.

Offline oscar

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Re: GA/TN: move location of state line on TN 68
« Reply #1 on: February 27, 2020, 09:10:54 pm »
Looks like the marked state line (confirmed by the Polk County welcome sign) crosses the northern corner of the Toccoa Ave./ Harpertown Rd. intersection, which is where GA 5 makes a turn and also GA 60 begins. Would not over-simplify things to just move the south end of tn.tn068 to that intersection, and get rid of the ga.tn068 route file.

Aside from the pavement markings and the state line signs on both sides of that intersection, some but not all of the online maps in the Waypoint Editor have the state line cutting through the intersection.

This is yet another reminder that online maps (especially Google Maps, which I've found to be a major offender) often misplace borders, and signage can be more accurate.

Good catch!
« Last Edit: February 27, 2020, 09:50:20 pm by oscar »

Offline michih

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Re: GA/TN: move location of state line on TN 68
« Reply #2 on: February 28, 2020, 02:08:30 am »
This is yet another reminder that online maps (especially Google Maps, which I've found to be a major offender) often misplace borders, and signage can be more accurate.

I think that OSM seens ti be most accurate on this in general.

Offline neroute2

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Re: GA/TN: move location of state line on TN 68
« Reply #3 on: February 28, 2020, 06:09:16 pm »
This is yet another reminder that online maps (especially Google Maps, which I've found to be a major offender) often misplace borders, and signage can be more accurate.

I think that OSM seens ti be most accurate on this in general.
Not in this case it ain't...

Offline US 89

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Re: GA/TN: move location of state line on TN 68
« Reply #4 on: March 08, 2020, 10:24:48 pm »
I think that OSM seens ti be most accurate on this in general.

Disagree, especially in mountainous areas. In many cases where a state/county line runs along a ridge or drainage boundary, OSM uses a very rough approximation for the line. One example would be at Guardsman Pass in Utah - the actual county line hits UT 190 at that parking area at Guardsman Pass, not where OSM's displayed line is.

Offline yakra

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Re: GA/TN: move location of state line on TN 68
« Reply #5 on: March 09, 2020, 05:13:39 am »
Various online Maps can differ quite a bit in where they Place boundaries. Sometimes osm will show, say, County and state lines that are a bit off at what's otherwise the same location. GIS shapefiles can sometimes be our best source for this data.

Offline oscar

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Re: GA/TN: move location of state line on TN 68
« Reply #6 on: March 09, 2020, 08:38:19 am »
I tend to default to OSM on borders. If it's off, usually the error will not be a big deal, it'll just move mileage from one state's system to another. But here, neroute2's field check gives us a chance to get rid of a supposed Tennessee route segment in Georgia, so more precisely locating the border makes a difference.

Offline mapcat

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Re: GA/TN: move location of state line on TN 68
« Reply #7 on: May 14, 2020, 03:49:16 pm »
https://github.com/TravelMapping/HighwayData/pull/3870

I went with the location of the blue line in GMSV.
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