No matter what mode of transportation is being used, smells get a lot of fellow travelers nominated for the most annoying.
Some of these people are eating highly aromatic foods… and not the pleasant sort.
They eat tuna, or smelly cheeses, never thinking about how the person in the next seat is turning green.
Others wear too much perfume and leave other passengers gagging on the fumes.
Or worse, they leave their hygiene at home and emit body odors that offend everyone around them.