Caffeine doesn't do much to wake drivers up, but it can have a major impact on reducing driver error, a new Australian Defence Force study shows.
The research looked at ways of reducing fatigue in individuals and teams, particularly in army vehicles, using caffeinated chewing gum.
The study results were presented at the Australian Psychological Society Conference today.
Participants were kept awake for 50 hours and during that time were required to drive 15 times in a simulated vehicle for 40 minutes each time.
Half the group was given the caffeinated gum, with the others were given a placebo.
The gum was used because it only takes 10 minutes for most of the dose to be absorbed by the brain and lasts for 90 minutes, whereas drinking coffee takes between 30-90 minutes to be absorbed for an unpredictable amount of time.
Levels of drowsiness were measured using a spectacle frame-mounted infrared sensor which registered the frequency of blinking. Changes in speed and the number of times drivers switched lanes were used to measure driving performance.
Researchers found a link between increasing drowsiness and driving errors in the placebo group, while the other group had fewer driving mistakes though they also grew more tired.
"In real life you often don't have the luxury of stopping when you're tired, so you need some compensatory strategies to combat cognitive fatigue, and when you're driving this is particularly important because of road safety," defence researcher Kayla Johnson says.
Defence Force chief scientist Dr Alex Zelinsky says he believes the study has relevance outside the army, such as for emergency services and long-haul transport drivers.
The study was a collaboration between researchers in the UK, US, Canada, New Zealand and Australia.