It appears that OSX 10.8 removed the tar --tape-length flag, and I see no other way to create split tar archives as described in this hint.
One alternative is to create split zip files using the zip tool provided with OS X.
As described in man zip, the resulting files are not just one big zip file that has been split into pieces, and thus they cannot gracefully be concatenated back together as described in another hint, so this differs from simply using the split command. I needed to send files to a Windows user with 7zip, so split was probably out of the question.
To get 4699717632 byte files that would fit on a DVD I used zip -s 4482m output.zip /source/directory
Mac OS X Hints
http://hints.macworld.com/article.php?story=20130319203935963