I believe the answer is that a passenger has 15 minutes for the bus to wait and then it leaves if they are not at the right spot..period. We have been held up a number of times by people who have no consideration and they should be warned of the consequences for being late. One time time in Rome on a tour van with about 14 passengers we had one couple that always was late returning and it was beyond annoying. Finally at one stop they came back 1/2 hour late and two guys on the van told them to get off. When they resisted they threatened them and they got off. all clapped. There has to be consequences for acts of disrespect for others and it should carry to all circumstances.