In the video at http://communities.bentley.com/products/road___site_design/w/road_and_site_design__wiki/18003.video-openroads-integration-with-gpk-file, the presenter notes at about 25:49 that Geopak SS3 .722 won't save single lines as alignments, so there was a priority build .723 developed to allow this. Does this priority build also allow simple arcs to be saved as alignments?
Alternatively, I suppose I can create an alignment on my own in COGO based on the curve; there will be no reason to believe that it will disappear in the future, right?