National Forest Road System
The National Forest Road System consists of more than 380,000 miles of roads within the United States, primarily facilitating travel through, or entrance and exit from, United States National Forests. The TIGER import has incorrectly tagged most of these ways with highway=residential, name=name of reference, and ref=* completely unset. Not all (in fact, many) of these routes were never mapped or fully mapped by the TIGER import. Not all routes are signed along their entire length.
There are generally two signed types of National Forest Road.
National forest primary routes
National Forest Primary Routes (also widely referred to as National Forest Highways or Forest Highways) are signed with a brown Isosceles trapezoid, wider at the top. Most have 1, 2, or rarely, 3 digit identifiers. They are usually unique to the National Forest in which they exist.