Anyone have an idea of what percentage of US roads aren't mapped

Discussion created by christopher.richmond on Feb 29, 2012
Latest reply on Feb 29, 2012 by JRobinson-esristaff
This question came up from folks in the field who noticed roads that aren't in the StreetMap network.  I realize not all roads are in the geometric network but does anyone know where I can find documentation on about what percentage of US roads are included in the network?