If you have a desk job, nodding off at your keyboard could get you a lousy performance review. But if you’re a transportation worker, on-the-job grogginess could actually put people’s lives at risk.

A new poll from the National Sleep Foundation finds many transportation workers — bus drivers, pilots, train operators and the like — are getting so little sleep that they’re too tired to do their jobs properly.

Dr. Shelby Freedman Harris, director of behavioral sleep medicine at Montefiore Medical Center’s Sleep-Wake Disorders Center in New York City, believes the rotating shifts many transportation employees have to work are problematic, and she adds they often aren’t given enough time off between shifts to rest up.

“We’re asking people to work when they’re predisposed to being [asleep],” Harris said. “You can’t just turn the switch off that it’s time to go to bed.”

So which transportation workers said sleepiness affects their job performance at least once a week?

Ten percent of bus, taxi and limo drivers gave that answer; truck drivers made up 15 percent; and pilots made up 23 percent. According to the survey, however, the occupation most affected by lack of sleep is train operator. Twenty-six percent of these workers responded that sleepiness affects them on the job.

Guess a lot of us will start to take the bus more often now, huh?