SACRAMENTO (CBS) – If you’re feeling more tired than normal today, you are not alone. The American Academy of Sleep Medicine says 45% of adults report feeling unusually fatigued on the day they return to work in January.

That makes it the second sleepiest day of the year. New Year’s Day is number one, with 57% saying they are “extremely tired” or “somewhat tired.”

Drowsiness may not affect work performance too much, it certainly creates a danger for those driving to and from work.

A 2018 study found that drowsy driving led to more car crashes than previously thought. Previous government estimates put drowsiness as a factor in one to two percent of accidents, but a new study from AAA finds that number is much higher. It determined that nearly 10 percent of crashes can be blamed on drowsy driving.

AAA’s William Horrey says getting only four hours of sleep at night can have an effect similar to driving drunk.

“You might have sluggish responses, you might not be able to keep the vehicle in the lane as well as you should,” Horrey said.

Government figures show 35 percent of U.S. drivers don’t get the recommended minimum of seven hours of sleep every night.