Sorry Al, but I would regard myself as knowledgeable on transport matters too and I never heard of POP.
I agree with Donnybrook Observer. It would be more valuable for people like yourself who are remote from what is happening on the ground in Ireland to ask questions rather than make outdated ill-informed statements.
We all know there are Irish Americans who still think we go around in horse and cart looking for leprechauns. Ireland has moved on and those who have left our shores are inevitably not with the times in understanding the issues that we have to debate.
By the way, there are about 2000 drivers in Dublin Bus, so reintroducing conductors would require 2000. The use of flying squads of ticket inspectors, as also done by Luas and Iarnrod Eireann, is clearly the most cost effective way to enforce compliance on ticket payment.