OpenStreetMap
On the German mailing list one mapper recently asked how to tag a dirt road:
http://lists.openstreetmap.org/pipermail/talk-de/2011-October/089483.html
There are many dirt roads with local importance which should be tagged as tertiary due to their importance, but also as track due to their road condition:
Let's take the Mosquito Pass in Colorado - it is a major connection between Fairplay and Leadville that looks like presented in these videos:
http://www.youtube.com/watch?v=sOOzE2_qrNg
http://www.youtube.com/watch?v=4owzKpG4JPU
I wish we had a tagging mechanism for dirt roads combining importance (highway=*) and road condition (tracktype=* or 4wd=easy/moderate/difficult).
Any suggestions?
Discussion
Puna mula sa stevage noong 10 Oktubre 2011 sa ganap na 23:39
Interesting question. I'd ask on help.openstreetmap.org.
Puna mula sa z-dude noong 11 Oktubre 2011 sa ganap na 01:27
If you can't use a normal car, then I'd tag it as a track. You don't want people in normal cars getting stranded because their GPS told them to drive on a dirt road. http://www.torontosun.com/2011/10/04/stranded-woman-recounts-tale-of-survival
If you can use a normal car, then tag it as a road, surface = gravel or surface = dirt (potlatch has this in the simple editor)
There's some proposed 4wd tags.
osm.wiki/Proposed_features/4WD_Only
osm.wiki/Tag:4wd_only%3Dyes
Puna mula sa Pan noong 11 Oktubre 2011 sa ganap na 05:28
Here in DRC, even most of the primary roads are dirt tracks. it is difficult to know how to tag them.
Puna mula sa Diomas noong 11 Oktubre 2011 sa ganap na 06:53
highway=track doesn't tell us anything about accessibility - it can have excellent smooth surface, it just mean that the road leads to "nowhere": road in the forest to some single hut or a road in the field to some lake. So it's just about the status of the road.
In other words, if the road has a name/number, or if it's the only way to get to some hamlet/village/town, then it can't be highway=track whatever surface it has. Otherwise it should be at least highway=unclassified.
You can also do some check: if removing highway=track cause some highway=unclassified|residential etc way to be not connected to other roads, then the road you just removed is not a highway=track.
To define a surface there is a "surface" tag - it can be applied to any highway: from highway=trunk to highway=footway.
To define a physical accessibility of the road there are many tags can be used:
tracktype (for tracks only),
smoothness,
and different proposals like 4wd, 4wd_only, surface:grade etc
Puna mula sa Richard noong 11 Oktubre 2011 sa ganap na 07:09
highway=tertiary, surface=unpaved | gravel | dirt | what-have-you.
Puna mula sa maxolasersquad noong 11 Oktubre 2011 sa ganap na 15:27
Richard ++
Puna mula sa marscot noong 12 Oktubre 2011 sa ganap na 19:29
I would tag them highway=track but they are as you say tertiary tracks, maybe this points to a new type of track that needs to be drawn
Highway=track
track_type=tertiary_grade1or 2 or 3 or 4
Puna mula sa Jean-Marc Liotier noong 14 Oktubre 2011 sa ganap na 09:31
Richard's "highway=tertiary, surface=unpaved | gravel | dirt | what-have-you" is the correct answer. Here in Europe we are not used to anything but pavement, whereas in Africa I have often seen tertiary and even secondary dirt roads. The place of the road in the network hierarchy is the primary indicator for the highway tag - road surface is less important.