More than likely the supervisors or higher ups. I have heard them having these discussions since I have began listening to IDOT. They will use ID's which are not the typical Flora-30 or Flora-1 it was like 72-21, 72-xx . This was in D7 - Effingham region which goes all the way up to Decatur area, I know they were discussing conditions on 121.
That makes sense as I've heard some units around here with unit numbers 52xx if I remember correctly and I'm in IDOT Dist 5.