I’ve been updating OSM roads and trails based on the US Forest Service Motor Vehicle Use Maps (MVUM). The USFS MVUM is “the legal instrument that shows where people are allowed to drive”. There are many roads shown in OSM that are not open to motor vehicles, but not properly tagged. There are also few roads and quite a few moto trails missing.

If there’s a road that is not open I just add motor_vehicle=no. It’s possible that it could be access=no, but often it’s still open to bikes & almost always still open to foot or horse traffic. Since all I really know from the MVUM is motor vehicle access that’s all I usually add. I’ll update the ref tag if it needs it.

The data sources I’ve found for this are a nationwide SHP file and geopdf’s for individual forests.

The shapefiles are available here: https://data.fs.usda.gov/geodata/edw/datasets.php?xmlKeyword=mvum Since that’s the whole country, I use ogr2ogr -clipsrc bounds outfile infile [note the backwards order for the files] & clip to a manageable size. The whole state of Colorado seems to be a manageable size. I don’t directly import anything from the shp file, but If I see a fairly long trail or road missing I’ll copy and paste into a josm layer.

A web search of the forest name & MVUM will yield a page like this: https://www.fs.usda.gov/detail/psicc/maps-pubs/?cid=stelprdb5177824 (I just noticed that page has SHP files too.) I convert these to tif & load the image into JOSM. gdal_translate -co TFW=YES file.pdf file.tif JOSM is really sluggish with this so if someone has a better way I’m all ears.

My 1st step is usually to load the geopdf into Qmapshack overlayed with my custom OSM map built with mkgmap. I can fairly quickly see differences this way, easier than in JOSM. Once I know what part of the map needs work I load JOSM with the tiff image and make the OSM changes needed. I’m starting to use the SHP file more & may use the tif less.

I have brought Gunnison, San Isabel, and Rio Grande NF up to date.