Drowsy driving is a significant problem: According to the CDC, in the United States as many as 6,000 fatal crashes each year are caused by drivers who fall asleep at the wheel. One possible cause, suggests a small study from RMIT University in Melbourne, Australia, is that the constant, steady, low frequency vibrations in cars can make you sleepy and affect your alertness and concentration after just 15 minutes.
Researchers tested 15 volunteers in a virtual simulator replicating the experience of driving on a typical two-lane highway – once with low frequency vibrations and once without vibrations. During the 60-minute tests, they measured study participants’ heart rate variability to gauge drowsiness. When we’re tired, it’s psychologically and physiologically more difficult to perform mental tasks, so the nervous system attempts to compensate, leading to changes in heart rate.
The researchers detected signs of drowsiness within 15 minutes of starting the vibration. Within 30 minutes, study participants required substantial effort to remain alert, and the tiredness increased progressively, peaking at the end of the test. Car seat designs that disrupt normal car vibrations could help decrease drowsy driving in the future, according to the researchers.
Sourced from: Ergonomics