Who has the right to ask a passenger carrying durian to get off a bus?

At every metro station in Ho Chi Minh City, signs in both Vietnamese and English remind passengers that durian and jackfruit are not allowed on trains.

Public buses in the city do not appear to carry similar warnings. That became an issue for me yesterday afternoon when I took the bus home after work.

The electric bus was smooth and quiet, with cool air-conditioning as it moved through the city. The ride was free under the city's public transport development policy, and there seemed to be more passengers than before.

At one stop, two young men boarded, carrying a large sack with some difficulty.

Before the attendant could ask what was inside, a woman sitting behind me said: "There's a smell of durian."

Several passengers immediately put on their masks to avoid the strong smell.

The attendant then told the two men: "If anyone on the bus objects to traveling with durians, I would have to ask you to get off."

But no one said anything.

The two men dragged the sack toward the back of the bus, stopping near where I was sitting. The smell quickly became overwhelming. I eventually had to get off at the next stop.

That left me wondering: Who has the right to ask a passenger carrying durian to leave a public bus?

If passengers are allowed to bring durian onto buses, should there at least be clear rules about how it must be packaged or transported? Or, like on the city's metro system, should buses simply have a clear "no durian allowed" rule?

A clear policy would save passengers, attendants and the people carrying the fruit from having to negotiate the issue on the spot.