For many South Africans, getting behind the wheel after a long day is simply part of the routine. You may have left home before sunrise, spent hours at work, dealt with traffic, collected the kids, run errands, and still have a long drive ahead of you.
But there is one road safety risk that is easy to overlook: being tired.
New research from Discovery Insure suggests that poor sleep could be one of the biggest blind spots when it comes to motor vehicle accidents. The Discovery Insure research analysed four years of sleep, driving, and accident data from more than 10,000 Discovery Insure drivers, making it one of the largest studies of its kind in South Africa.
The findings point to a simple message for South African motorists: road safety may start before you even get into the car, with how well you slept the night before.
Discovery Insure research links poor sleep to accident risk
According to Discovery Insure, poor sleep was strongly associated with motor vehicle accident risk.
Robert Attwell, CEO of Discovery Insure, says sleep has traditionally received less attention in road safety than risks such as alcohol, speeding, and distracted driving.
“Breathalysers can detect alcohol impairment, a visible and well-understood risk factor for accidents. Driver fatigue, by contrast, has until now been largely invisible,” says Attwell.
The research found that poor sleep can affect concentration, reaction time, and decision-making – all of which are important when driving through busy South African roads.
Discovery Insure says poor sleep was up to five times more predictive of motor vehicle accident risk than traditional insurance risk factors considered in isolation.
That does not mean every tired driver will have an accident. Rather, the findings suggest that sleep patterns could be an important factor when understanding and managing driving risk.
It is not just one bad night.
One of the most important findings from the Discovery Insure study is that drivers should not only worry about getting too little sleep on a single night.
The bigger concern can be sleep debt – the amount of sleep a person loses over several consecutive nights.
Almost 30% of Discovery Insure drivers were found to accumulate some level of sleep debt while driving. Around half of sleep’s overall impact on accident risk was linked to chronic poor sleep rather than one isolated night.
The difference can also be significant. Drivers who maintained less than one hour of sleep debt over three consecutive nights had up to a 36% lower accident risk than drivers carrying five or more hours of sleep debt over the same period.
In everyday terms, regularly cutting your sleep short because of work, late-night responsibilities, studying, social commitment,s or simply spending too much time on your phone could have consequences when you eventually get behind the wheel.
How much sleep do drivers need?
The Discovery Insure research highlights several sleep habits associated with lower accident risk.
According to the findings:
- Drivers who regularly get seven to eight hours of sleep are around 32% less likely to be involved in an accident than those who sleep too little.
- Drivers who go to bed within roughly one hour of their ideal bedtime each night are up to 36% less likely to have an accident than those with irregular sleep patterns.
- Drivers who get adequate Rapid Eye Movement (REM) sleep experience around a 14% lower accident risk.
The message is not that motorists need a perfect sleep schedule every night. Rather, building healthier and more consistent sleep habits could form part of a broader approach to road safety.
Tired driving is a road safety issue, too
Most people understand that drinking and driving is dangerous. Many drivers will also think twice before getting behind the wheel after having too much alcohol.
But fatigue can be harder to recognise – and easier to ignore.
A 2024 survey found that almost 90% of adults would avoid driving after having a few drinks, while only 50% said they would do the same after getting poor sleep.
Research published by the University of Pennsylvania also found that being awake for more than 16 hours can impair driving ability to a level comparable with being at or above a 0.05% blood alcohol concentration. This is particularly relevant in South Africa, where 0.05% is the legal blood alcohol limit for most drivers.
The comparison is important because tiredness can affect the very abilities drivers rely on most: staying alert, reacting quickly, judging distances, and making decisions.
The wider road safety picture in South Africa
Driver fatigue is only one part of a much bigger road safety challenge.
Globally, road crashes remain a major cause of death and serious injury. The World Health Organization (WHO) estimates that approximately 1.16 million people die in road traffic crashes every year, while between 20 million and 50 million more suffer non-fatal injuries.
The WHO identifies several major road safety risks, including speeding, alcohol and drug impairment, distracted driving, unsafe vehicles, and inadequate road infrastructure.
In South Africa, the economic impact is also significant. Road crashes cost the economy an estimated R205 billion in 2023, equivalent to about 2.7% of GDP, according to information presented to Parliament.
This search for practical ways to reduce crashes is particularly important.
For motorists, the idea is fairly straightforward: getting enough sleep is not only about feeling better the next morning. It can also be part of preparing yourself for a safer journey.
As Attwell puts it, “Every safer journey begins the night before.” There is no complicated technology or expensive equipment required to start taking fatigue seriously.
Before a long drive, motorists can make a few simple checks:
- Ask yourself whether you are genuinely alert enough to drive.
- Avoid starting a long journey after several nights of poor sleep.
- Take regular breaks on longer trips.
- Do not assume that opening a window, turning up the music, or drinking coffee will fully solve severe tiredness.
- If you feel yourself struggling to keep your eyes open or concentrate, stop driving and rest.
- Plan long-distance trips around adequate sleep rather than treating sleep as something to fit in afterwards.
For families, employers, and professional drivers, the issue is even more important. A driver who is under pressure to work long hours or complete a journey despite being exhausted may not always recognise just how impaired they have become.
Road safety starts before the engine starts.
South African road safety conversations often focus on speeding, drunk driving, reckless driving, and distracted driving. These remain critical issues. But the Discovery Insure research suggests that sleep deserves a place in that conversation too.
You might have a roadworthy vehicle, wear your seatbelt, obey the speed limit, and keep your phone away while driving. If you are struggling to stay awake, however, your ability to respond safely to what happens on the road can still be compromised.
For drivers heading to work on an early Monday morning, parents doing the school run after a difficult night, truck and taxi drivers working long hours, or anyone preparing for a long-distance trip, the advice is simple:
Before you worry about the journey, make sure you have had enough sleep for it. As Attwell concludes, healthier sleep habits could help more South Africans arrive safely, reduce the burden on families, and contribute to safer roads for everyone.
