Great, thanks! Looks about right; the project documents do seem to imply that the center island is intended to be traversable by trucks (HGVs), so perhaps it would indeed qualify as a mini-roundabout, but perhaps a local mapper can follow up and clarity.

To note, the planning map in the documents you found contains considerable detail (landcover, pavement surfaces, lanes, turn indications, crossings, etc) that would no doubt be useful for OSM especially in lieu of updated aerial or ground-based imagery. However, I'm not clear on the explicit licensing status, given OSM's very conservative policies in this regard. Given FLDOT has an official OSM account https://wiki.openstreetmap.org/wiki/User_talk:FloridaDOT perhaps it would be worth asking as to the document's provenance, and whether formal permission has been or can be granted?