If hell is other people, then mass transportation must be the ninth circle of damnation.

Stepping into a plane, train, or bus means exposure to the tics and bad habits of dozens, even hundreds, of others. And they're all so, so, close by.

The transit fare management company Genfare released recently the results of a survey that ranked the top transportation irritations by mode of travel. Music played loudly was up there, as were bare feet on a plane and phone conversations on a train. Some of the bad behaviors were nasty: Body odor, for example, concerned 26 percent of fliers and 41 percent of public transit travelers. Some activities — like being drunk while traveling — were self-evidently annoying, while others seem subjective. Is it bad manners to take shoes off on a flight? Not a problem, 64 percent of respondents said. Socks, though, should stay on.

A takeaway from this list could be that people aren't that good at being around others. Actions like kicking seats, which 53 percent of those surveyed said was their top pet peeve, are so evidently inconsiderate, it's stunning people do them.

On the other hand, a few top gripes suggest that the complainers are the ones with the problem. Of those surveyed, 23 percent said their greatest annoyance while flying is a baby crying. Empathy, anyone? Most often, parents are doing their best to quiet a child who's the center of attention on a flight.

Perhaps some of the proximity problems arise from another statistic: Nationwide, about 76 percent of Americans commute by car — very often all by themselves. (In the Bucks, Chester, Delaware and Montgomery Counties, car commuters number closer to 80 percent, according to the census.)

Alone in the car, you can play the music loud. Push back your seat. Go ahead and pick your nose. No one is going to complain.

Since Americans spend most of their time traveling alone, is it possible we've gotten out of practice doing it together?

The study's results were drawn from 2,000 Americans who fly at least twice a year. Here are the top 10 biggest complaints from three different modes of travel, and the percentage of people who complained about them.

Flying

  1. Kicked seats — 54 percent
  2. Crying baby — 27 percent
  3. Body odor — 26 percent
  4. Talking passenger — 23 percent
  5. Inattentive parents — 21 percent
  6. Drunk passenger — 18 percent
  7. Seat pulled back or leaned on — 17 percent
  8. Snoring — 15 percent
  9. Rushing to get off the plane upon landing — 15 percent
  10. Reclining seat — 15 percent

Public transit

  1. Talking loudly on the phone — 54 percent
  2. Body odor — 41 percent
  3. Playing music without headphones — 29 percent
  4. Taking up seats with bags — 28 percent
  5. Not giving up seats to the elderly — 22 percent
  6. Blocking exit doors — 19 percent
  7. Talking passenger — 18 percent
  8. FaceTiming without headphones — 18 percent
  9. Putting legs or feet on a seat — 16 percent
  10. Eating smelly food — 15 percent

Ride sharing

  1. Aggressive driving — 44 percent
  2. Driver talking on the phone — 32 percent
  3. Messy car — 31 percent
  4. Braking too hard/accelerating too fast — 29 percent
  5. Talking driver — 28 percent
  6. Driver's music — 25 percent
  7. Driver holding phone while driving — 20 percent
  8. Driver eating — 13 percent
  9. Driver asking for a good rating — 12 percent
  10. Driver asking for a tip — 10 percent