The Transport Accident Commission of Victoria estimates that about 20% of fatal car crashes in Australia are caused by driver fatigue.
A growing body of evidence suggests that gentle vibrations made by car seats during a drive can lull the brain and body and contribute to feelings of sleepiness.
To test the theory, a study from Melbourne's RMIT University hooked volunteers to a virtual driving simulator and tested them once with low frequency 4 to 7 hertz vibrations, and once without.
Volunteers showed signs of drowsiness within 15 minutes of the vibrations, as indicated by their heart variability. It became significant at 30 minutes, with participants becoming sleepier until the end of the 60-minute test.
Researchers believe one explanation could be that the brain becomes synchronized with the vibrations and enters the early stages of sleep.
It's also been suggested that some frequencies may keep people awake instead of lulling them to sleep. But to harness these "good vibrations", more work is needed to examine a wider range of frequencies.