According to new research, it takes just 15 minutes for car vibrations in order to make drivers feel tired behind their wheel.
The study was published in Ergonomics and surveyed 15 healthy young adults as they were each placed in a virtual simulator that produced vibrations similar to the ones a vehicle might create.The participants were then sent into a simulator that did not emit any vibrations, followed by vibrations again at 4-7 Hz. The total experiment and exposure to the various vibrations lasted one hour.
The results showed that every subject became more drowsy based on HRV (Heart Rate Variability) and KSS (Karolinska Sleepiness Scale) data.All 15 felt sleepy within 60 minutes of exposure to the vibration, yet according to researchers, most became drowsy within 15-30 minutes.
Mohammad Fard (study author) explained what causes people to feel drowsy from car vibrations.
We suspect that some frequencies of vibrations trigger drowsiness, particularly those near the frequency of theta brainwaves, which occur at the early stages of sleep, he explained. The frequency of theta brainwaves was determined by our team (i.e. The frequency range from 4 Hz to 7.8 Hz, and we found that these vibrations cause significant drowsiness in less than 30 minutes.
While this might sound alarming, scientists acknowledge the study group was small, and that more work is needed to be done to better understand the effects of car vibrations. The KSS (Karolinska Sleepiness Scale), which is subjectively rated the participants‘ level of drowsiness leaves room for error. Fard explained that KSS is used extensively in sleep research to describe changes in drowsiness over time.
Plus, what this study reveals may actually contribute to combating the issue straight on. The researchers said their evidence could help take steps towards making cars safer, by redesigning vehicles to filter out vibrations that cause drowsiness.
SECURE DRIVING
It is dangerous to drive while you are tired.The National Highway Traffic Safety Administration estimates that drowsy driving was responsible for 72,000 crashes, 44,000 injuries, and 800 deaths in 2013alone.
Fard explained that our bodies are exposed to many vibration frequencies while driving. This is not the only range we looked at. We have yet to investigate how these other vibration frequencies interact with the bad vibrations, but we think they are likely to dilute their effect.
Hence under normal driving conditions, it is likely to take much longer than 30 minutes of driving before the vibrations make the driver drowsy.
However, he did say that if a driver becomes aware that theyre starting to feel drowsy, they should not continue to drive. It is safer to stop and take a power nap.
If youre feeling tired at the get-go, dont get behind the wheel, he added.If you feel sleepy while driving, pull over and get a cup of coffee or ask someone to finish the drive. Most importantly, focus on getting efficient sleep each night, too.
As Fard and his team continue to expand their research, he remains optimistic about improving driver alertness on the road: We hope that it will be possible to develop new vehicle design guidelines that will require manufacturers to eliminate those frequencies of vibration that contribute to driver drowsiness.
