Every school duplicate that Arriva run are still 'open door' (except for some S43 and S54 journeys in North Tyneside).

This is because Arriva don't have many DBS checked drivers (which you can't run a closed door service without a DBS check). This is why you don't see the 'S' prefix on most - infact none in Durham County.

Buses provided by GNE or Stanley Travel that run in tandem with Arriva journeys are closed door so they do run with the 'S' prefix.