osmandapp/OsmAnd-resources — pull request #39 by cdavila (2013-08-23 10:25:54+00:00)
Title: Addition of several unpaved road types to avoid_unpaved profile as well ...

...as some barrier types
Unpaved road types added are quite common in OSM data, as a filtering of planet shows. Below figures are only for residential highways:
60998 gravel
31056 ground
24754 dirt
21959 paving_stones
10772 sand
9281 compacted
1273 pebblestone
1100 grass
346 mud
227 earth
224 fine_gravel
182 wood