About a quarter of pilots and 23 percent of train operators questioned in a National Sleep Foundation poll admitted that sleepiness had affected their job performance, compared to 17 percent of non-transportation workers.

And about 20 percent of members of both professions said they had made a serious error on the job because of their sleepiness.

"The margin of error in these professions is extremely small. Transportation officials need to manage sleep to perform at their best," said David Cloud, the CEO of the Virginia-based foundation.

Pilots and train operators also reported six times more car crashes than other workers because of sleepiness during their commutes to and from their jobs.

"Transportation workers are somebody that we trust to get us from one place to another and when there is a problem, when they make errors the results can be catastrophic, so any indication that they are sleepier than other people, I find it disturbing," said Thomas Balkin, a sleep researcher from the Walter Reed Army Institute of Research who worked on the poll.

"I don't, however, find it surprising," he added.

Like doctors, nurses and other people working in 24-hour operations, transportation workers' erratic schedules and turnarounds between shifts may not be conducive to optimal sleep, and long commutes can also be a sleep stealer.

Lack of sleep is a common problem with one in 10 Americans admitting to falling asleep at an inappropriate time, such as behind the wheel or in a meeting, according to the foundation.

But the number is higher for transportation workers. Half of the pilots and two-thirds of the train operators questioned in the poll said they rarely get a good night's sleep on work nights, more than all other workers polled.

Forty-four percent of train operators and more than a third of pilots said their work schedules don't allow them to get enough sleep and only six percent of pilots said they work the same schedule each day.

The time between shifts is also shorter with transportation workers having less than 13 hours, while people in other types of jobs have an average of 14.2 hours. Pilots said that if they had another hour they would use it to sleep.

Despite their best efforts to get more rest, 11 percent of pilots, train operators, and bus, taxi and limo drivers were found to be "sleepy," compared to seven percent of non-transport workers, according to the study which used an assessment tool used by doctors to determine their state of wakefulness.

"Even when they sleep they might be sleeping with one eye open, realizing that they are subject to be called to wake at any time," said Balkin.

Lack of sleep has an impact on cognition, judgment, risk taking, problem solving, awareness, reaction times and mood.

"These things are all reduced when we are deprived of sleep, or our sleep is restricted," Balkin explained. "You don't have to fall asleep to make a critical error."

He added napping and the judicious use of caffeine can help.

More than 1,000 adults were questioned in the poll conducted by WB&A Market Research, including 292 non-transport workers, 202 pilots, 203 truck drivers, 180 rail transportation workers and 210 bus, taxi and limo drivers.

(Reporting by Patricia Reaney; editing by Paul Casciato)

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