After alot of research, I found that the elevated intersections were removed with igo version 2009 2q. They say that there are some elevated bridge or road in major cities but I cannot verify. If anyone have 2010 2q maps with elevated road I would like to know.
The elevated road are not in the dem folder. I checked my 2007 version and the dem folder is empty and I have elevated intersections. I did check for hidden file in the folder.