Driver fatigue is a significant contributory cause of traffic crashes worldwide.

“Fatigue is considered to have the same result as being under the influence of alcohol or drugs, and may cause the same harmful effects on the road,” warns Miles le Roux, transport engineer at N3 Toll Concession (N3TC).

Although fatigue (or drowsiness) does not always result in a driver falling asleep, or causing a crash, it undoubtedly influences a driver’s ability to react and make decisions in traffic. Fatigue results in poor judgement and decision-making and is often the cause of negligence and less tolerant behaviour on the road. “Driving in a fatigued state is extremely dangerous. Not only for the fatigued driver, but for everyone else on the road,” says le Roux.

N3 Toll Concession (N3TC), the company managing the N3 Toll Route between Heidelberg in Gauteng and Cedara in KwaZulu‐Natal, commissioned the CSIR in 2011 to investigate, over a five-year period, the role fatigue plays in causing crashes on the route between Warden and Villiers in the Free State. As part of the study, 790 crashes, involving heavy vehicles, public transport and light vehicles, were recorded (over a five-year period) on this particular 100 km stretch.

Most of the crashes occurred while the vehicles were travelling north, in the direction of Johannesburg and in clear weather. Despite traffic volumes being lower at night, the majority of crashes occurred during night time, with the primary peak of crashes (mainly involving heavy vehicles) occurring in the early morning hours (between 03:00 and 08:00). A secondary peak occurred early evening (between 18:00 and 21:00).

“These findings indicated that crashes tend to take place under circumstances that are considered to be safe (clear weather conditions), but during hours that people are likely to be tired or asleep,” says le Roux.

Over the five-year study period, light vehicles represented approximately 51.4% of the crashes, whilst heavy vehicles were involved in 40.1% and public transport vehicles in 8.5% of the crashes. Types of crashes that are typically associated with fatigue include rear-end, run-off-the-road – and roll-over crashes (25%).

“Based on the study, it is estimated that 70% of crashes on this section of the N3 Toll Route potentially points to fatigue playing a role,” explains le Roux.

The study also included a driver behaviour survey which confirmed that most drivers recognise the onset of fatigue in that they start to yawn (32%); start to look for other things to do (29%); struggle to keep their eyes open (19%); blink their eyes (9%) or drive on sections of the road without remembering how they got there (2%).

Drivers participating in the study mentioned the following sections along the N3 Toll Route as areas where fatigue may be experienced:

• Between Warden and Villiers
• Harrismith
• Between Mooi River and Estcourt

“Considering the study results and keeping in mind that fatigue causes a decline in physical and mental performance, it is of the utmost importance that long distance travellers plan their trips, and allow ample opportunity to take regular rest stops, especially during periods when they are more at risk and along the regions where it has been indicated that fatigue may set in. Driver attitude and awareness will go a long way in preventing crashes and ensuring the general safety of everyone on the road,” advises le Roux.

Little or disturbed sleep prior to driving; irregular driving and sleeping hours; health concerns such as poor eating habits; diabetes and substance abuse; as well as physical vehicle factors such as poorly designed cabins in heavy vehicles not allowing sufficient fresh air circulation; becoming too warm/cold, or constant breathing of carbon monoxide from the exhaust emissions of vehicles, may all cause fatigue.

Furthermore, a too familiar road environment (such as roads frequented by long-haul drivers) may also lead to monotony and drivers losing concentration. “It is essential to consider these factors prior to – and during your trip,” says le Roux. “Always take the necessary steps to ensure that you remain driving fit and stay alert.”