Drivers who get behind the wheel with 4 to 5 hours of sleep pose a similar risk as drunk drivers, a new study reports.

The study, conducted by the AAA Foundation for Traffic Safety, used data obtained from NHTSA's National Motor Vehicle Crash Causation Survey. The researchers did not include crashes that occurred between midnight and 6 a.m.

National Sleep Foundation recommends adults ages 18 to 64 get between 7 and 9 hours of sleep each night. Six hours of sleep, the foundation says, “may be appropriate."

According to Bureau of Labor Statistics and CDC estimates, 18% to 25% (respectively) of adults in the U.S. do not meet this recommendation.

Approximately 97% of the drivers in the AAA Foundation study said they believe driving when sleep-deprived is a bad idea, indicating that sleep’s connection to drivers’ performance is nothing new to public knowledge.

Yet, in a public composed with 1-in-25 who report having fallen asleep behind the wheel in the past month, it is time for Americans to wake up to the dangers of sleep deprivation before getting behind the wheel.