Used to work on the 84 back in the late 80’s. People used to get it for a day trip out to Newcastle or Kilcoole (to see some of the sights from Glenroe). They would go all the way to the terminus and stay on the bus and go all the way back into town again.
I’m digressing slightly but there were also people who used the bus to go from Mass to Mass. The 11 and 13 used to have a good few of these nutters who’d start off at Mass at some unearthly hour in Adam and Eves, find a 7.30 mass then get the bus to a 8.30 mass on then to the 10 Mass in Home Farm Road and so on. They used to love Holy Days!
The longest Dublin Bus route is the 33, in particular the 0450 journey from Balbriggan which diverts from the normal route after Lusk and double runs via Donabate & Portrane re-joining the normal route again near Lissenhall. The total distance is just over 51km for this journey and it serves an incredible 116 bus stops!!. Other than that, the 65 City to Ballyknockan is the longest.