On Sat, Aug 22, 2015 at 6:09 PM, moltonel 3x Combo <molto...@gmail.com> wrote:
> On 22/08/2015, John Eldredge <j...@jfeldredge.com> wrote: > > So, if you are looking for a route without steep grades, a former > > railway is a natural choice. > > Do people actually do this ? Yes, I do. > It sounds like a strawman argument to me. > I do a fair bit of walking and cycling, and when planing a trip I look > at the global topographic data but it never occured to me to look for > railroads. Why use the local railroad hint when you've got the global > DEM data ? DEM is great for showing large differences in elevation, but it tends to suffer a bit when it comes to subtle cues. Compare http://www.openstreetmap.org/way/14953012 , http://www.openstreetmap.org/way/14939296 , http://www.openstreetmap.org/way/199770540 , and http://www.openstreetmap.org/way/14943691 to the roughly parallel highway OK 11. These segments are likely (but not yet formally proposed) to be an extension of the Osage Prairie Trail, closing the gap from metro Tulsa to the capitol of the Osage Nation and a yet to be determined distance farther north along the former railroad. That grade, just from standard railroad engineering practices, is unlikely to be steeper than 2% for any significant distance and extremely unlikely to be steeper than 4%. OK 11, however, is a rollercoaster of a highway with many steep grades, some of which are easily past 8%. The DEM really glosses over this thanks to Tulsa and Pawhuska only being about 100 feet difference in elevation. The intervening terrain is pocked with rolling hills and cliffs formed from erosion, with the highest point on the highway being about 1000 feet.
_______________________________________________ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
