New research suggests that younger drivers are more likely to get behind the wheel drowsy than drunk despite it being just as dangerous.

Researchers from Queensland University of Technology said Road safety researcher Chris Watling said driving sleepy and driving drunk were two risky behaviors linked to a comparable increase in crash risk, yet drivers perceived the dangers of each as vastly different.

"Research shows a blood alcohol content (BAC) of 0.05 per cent has the same effect as being awake for 17 hours, and a BAC of 0.1 per cent is roughly 20 hours, but drivers don't consider the impairment to be the same," researcher Chris Watling said in a statement. "In Queensland 20 percent of the state's fatal crashes were attributed to drunk driving and an estimated 15 percent to fatigued driving, although incidence rates of sleep-related crashes are often more difficult to pinpoint because of the absence of an objective test."

For the study, researchers which examined the perceptions of sleepy driving and drink driving of 114 drivers under 30 and 177 drivers over 30. They found young drivers were more likely to drive sleepy than drunk and more accepting of enforcement practices for drink driving than they are for sleepy driving.

"What this shows is that drivers, in particular young drivers, don't view equally the dangers of drunk driving and sleepy driving despite the crash risks being similar," Watling said.

Watling said younger drivers were also more likely to be impaired by sleepiness because of the natural developmental maturing of the body's sleep-wake systems in early adulthood.

"Given younger drivers are over-represented in crash statistics and more likely to be impaired by sleepiness, it is vital we look to increase their perception of the dangers of driving while sleepy," he said. "The positive take home message is that these results reflect the efforts of sustained drink-driving enforcement and community education campaigns that have changed social norms and reduced the acceptability of drunk driving."

The findings will be presented today at the 2015 Australasian Road Safety Conference on the Gold Coast, which runs until October 16.