Rick Bivins: Lionel made a 30 degree crossing in their SUPER O Track line. SUPER O is based on the 12 sections to make a circle, with 30 degree arcs. Both Lionel and Gargraves made adapter pins to mate regular tubular track to their brand of track. They are both similar in that they both use the rolled steel T-Rail tubular track form. K-line made a track style that looked like SUPER O (possibly a version of Kusan track that looks close to the Lionel SUPER O, but has black ties rather than the Lionel brown. Food for thought. Dennis M.
P.S. Remember that with tubular track, you can cut it anywhere and make the section you need very easily - No plastic roadbed or staggered track rails to deal with; then ballast as necessary.