<p><a href="http://blogs.esri.com/Support/photos/mapping_center_dec_2007/picture443.aspx" target="_blank"><img src="http://blogs.esri.com/Support/photos/mapping_center_dec_2007/images/443/secondarythumb.aspx" title="DRG map excerpt" align="right" border="0" hspace="5"></a>The map excerpt shown at right (click on it to see the details) shows an example of hollow cased roads.  The map is from a mosaic of USGS DRG image files.  The map specification requires that the cased road symbol contains a transparent gap.  The examples shown below were created with ArcMap 9.2 and used cartographic representations to re-create the effect on the USGS DRG map.