Shift workers could be accident prone

More than a third of night-shift workers were involved in near-crashes in an after-work test drive, researchers reported in the Proceedings of the National Academy of Sciences.

Nearly half of the 16 workers studied had their test drives cut short because they failed to maintain control of their vehicle.

The same drivers experienced zero near-crashes in a separate test conducted after they'd slept nearly eight hours instead of working.

More than 9.5 million Americans work overnight hours or rotating shifts. Drowsiness contributed to 21% of fatal crashes between 2009 and 2013.

Researchers, led by Charles Czeisler, M.D., Ph.D., chief of the division of sleep and circadian disorders at Brigham and Women's Hospital in Boston, sought to measure the effects on driving. They gauged drowsiness through eyelid movement and brain activity.

Researchers found sleep-related impairment became obvious among the post-work group within the first 15 minutes of driving. In all, 37.5% of night-shift workers used emergency braking maneuvers during their after-work test drive, 100% after 45 minutes into the test.