< Colorado
In Colorado, we do not use the dirt road type unless it is for 2 track roads, or unimproved roads.
([File:RoadPicN6.jpg|Example of a "2 track road." This would be set as a dirt road.])
If the road has been improved at all (meaning that it is a gravel road), we use the street road type. There may be special circumstances, so contact a local Area Manager with any questions.
See Colorado/Special roads for guidance in Colorado that may not be universal to all other states and territories.