Acute Sleep Deprivation and Risk of Motor Vehicle Crash Involvement

This study found that drivers who miss between one to two hours of the recommended seven hours of sleep in a 24-hour period nearly double their risk of having a collision.The report also found that drivers who miss 2-3 hours of sleep in a 24-hour period more than quadrupled their risk of a crash compared to drivers getting the recommended seven hours.

This is the same crash risk the National Highway Traffic Safety Administration in the USA associates with driving over the legal limit for alcohol.

The report says crash risk for sleep-deprived drivers increases steadily when compared to drivers who sleep the recommended seven hours or more:

• Six to seven hours of sleep: 1.3 times the crash risk
• Five to six hours of sleep: 1.9 times the crash risk
• Four to five hours of sleep: 4.3 times the crash risk
• Less than four hours of sleep: 11.5 times the crash risk

The report is based on analysis of a representative sample of 7,234 drivers involved in 4,571 collisions.

While 97% of participants told the researchers they view drowsy driving as a completely unacceptable behaviour that is a serious threat to their safety, nearly one in three admitted that at least once in the past month they had driven when they were so tired they had difficulty keeping their eyes open.