The most in-depth drowsy driving research ever conducted in the U.S. using footage of everyday drivers found that the percentage of crashes involving drowsiness is nearly eight times higher than federal estimates indicate, according to the AAA Foundation for Traffic Safety.“We do see some crashes here in Barton County that are probably related to the drivers driving while they are drowsy. It is just really hard to prove that is what caused the crash,” Barton County Sheriff Brian Bellendir said. “People get kind of hypnotized at night while driving which can cause people to get drowsy during the night.”The difficulty in detecting drowsiness following a crash makes drowsy driving one of the most under-reported traffic safety issues.