Durham doesn't have access to the Troy system, they're on the OneVoice Network. It -might- be a bus owned by the City of Troy Schools; that talkgroup is in the same range as the other City of Troy Schools operations. Unless, someone built a cross-system patch so the DMR radios that Durham uses can communicate with the P25 radios Troy uses.
Oh ok because I did hear the bus dispatcher say Durham bus and the number of the bus and then I heard the Durham bus reply back to the dispatcher on the Troy system