Discovery Insure research shows that poor and inconsistent sleep – particularly sleeplessness over several consecutive nights, known as sleep debt – is one of the strongest predictors of vehicle accident risk, being five times more predictive than traditional insurance risk factors. The findings have led to the launch of Vitality Drive Sleep Points to encourage healthy sleep habits and ultimately make South Africa's roads safer.
According to research by Discovery Insure, poor sleep could be one of the biggest threats to road safety. Based on four years of driving and sleep data, research shows that sleep deprivation for several consecutive nights is one of the strongest predictors of motor vehicle crash risk, highlighting an often overlooked factor that may help prevent vehicle crashes.
The research links four years of sleep data from more than 10,000 Discovery Insure drivers to their driving behavior and crash outcomes, making it one of the largest studies of its kind conducted in South Africa.
The findings led to the introduction of Vitality Drive Sleep Points, a new feature within the Vitality Drive program that rewards healthy sleep habits as part of Discovery Insure's commitment to helping make South African roads safer.
Robert Attwell, CEO of Discovery Insure, says, “Breathelyzers can detect impairment from alcohol, a clear and well-understood risk factor for crashes. In contrast, driver fatigue has been largely invisible until now.”
Image: stillsbytom:Robert Atwell CEO Discovery Insure
“Sleep affects concentration, reaction time and decision making, which directly impacts driving behavior and outcomes. Our research shows that poor sleep is five times more predictive of motor vehicle crash risk than traditional insurance risk factors considered separately. This points to a significant blind spot in how driving risk has traditionally been understood both locally and globally.”
Sleep debt is a powerful driver of accidents
One of the clearest findings is that it's not just one night of bad sleep that matters. Lack of sleep for several consecutive nights – known as sleep debt – has an even greater impact on crash risk.
Approximately 30% of Discovery insured drivers accumulate some degree of sleep while driving, with approximately half the effect of sleep on crash risk being associated with chronic poor sleep rather than an isolated night.
Discovery's research also found that:
Drivers who regularly get seven to eight hours of sleep are about 32% less likely to be involved in an accident than those who sleep too little. Drivers who go to bed within about an hour of their ideal sleep time each night are 36% less likely to have a crash than drivers with irregular sleep patterns. Drivers who experience sufficient rapid eye movement (REM) sleep have about a 14% lower risk of a crash.
Driving while tired requires the same amount of care as driving under the influence of alcohol.
Despite growing evidence, many people still underestimate the dangers of driving while tired.
A 2024 survey found that nearly 90% of adults would avoid driving after drinking a little alcohol, but only 50% said they would do the same if they had poor sleep.
Research also shows that being awake for more than 16 hours can impair driving while being equal to or exceeding South Africa's legal alcohol limit (0.05% blood alcohol).
“For years, road safety efforts have focused on risks such as speeding, distracted driving and drinking and driving,” Atwell says. “Our research shows that tired driving requires the same level of public awareness as the consequences can be just as serious.”
“Since 2011, Vitality Drive has used behavioral science and telematics to help drivers reduce their risk on the road, reducing crash fatalities among our best drivers by 80%,” Atwell says. “Adding sleep is a natural next step because it addresses a risk factor that has always existed but has been difficult to measure until now.”