WASHINGTON — Being greedy with seats and talking loudly on cellphones are two of the top pet peeves Americans have on public transportation, according to a new nationwide study.

The D.C.-based company KRC Research conducted the survey, examining the four behaviors that annoy commuters the most when they hop on a plane, train or automobile.

Fifty percent of respondents said the thing they hate the most is having to listen to someone talking on his cellphone.

Forty six percent are most bothered by passengers who don’t offer their seats to others who need them more, such as a someone with a disability or a senior citizen.

Forty one percent said the biggest faux pas is when riders take up a spare seat with personal items.

People eating a messy meal also registered at 41 percent.

KRC Research conducted its survey online in June with a sample of 500 adults, aged 18 years and older.