The problem of driver fatigue is difficult to address as many collisions that are driver fatigue related are blamed on other causes.

However, RoSPA estimates that driver fatigue may be a contributory factor in up to 20% of collisions.

In addition fatigue related road collisions are about 50% more likely to result in death or serious injury. The symptoms of fatigue, such as lack of alertness are most likely to cause issues on monotonous high speed roads like Motorways; where the consequences of a collision are serious, due to the forces involved in high speed collisions.

The definition of fatigue is generally considered to be a decline in mental and/or physical performance that results from prolonged mental or physical exertion, sleep deprivation and or disruption of the body’s internal clock.

There is a difference between fatigue and tiredness, however the medical definition and difference is unimportant; as the potential consequences are the same when combined with driving.

Fatigue increases reaction times, reduces concentration, alertness, and vigilance, all essential to the safe of performance attention based activities like driving.

Safe decisions are more difficult to make when we are fatigued. Fatigue can also cause stress, which can induce negative driving attitudes, and lead to unwarranted behaviour.

All drivers have at some time have felt sleepy whilst at the wheel, and are totally aware of the onset of tiredness. Some make a conscious decision to stop, take a break. Some decide to push on, and it is thought that those that do this have underestimated the risks involved.

Fatigue related road crashes are most likely to happen:

• On monotonous roads such as motorways; where higher speeds are involved
• When driving at a time when normally asleep, especially in the small hours
• If taking medicines that cause drowsiness, such as Antihistamines
• After long working hours, without rest, especially night shifts, or where shifts have been switched
• If suffering from a sleep disorder

Sleep Disorders

Sleep disorders often go undiagnosed, which is particularly dangerous.

One of the reasons for this is that if driver’s suspect that something is not right with their physiology, they fear the potential of losing their drivers licence. Those suffering from a sleep disorder, whether diagnosed or not, are at greater risk, from falling asleep at the wheel. Its has been estimated that that drivers, suffering from a sleeping disorder, are between 6 and 15 times more likely to have a road traffic accident than those without the condition.

The Problem of Driver Fatigue: How to Avoid Falling Asleep at the Wheel

Rule 91 of the Highway Code gives some advice.

Driving when you are tired greatly increases your accident risk. To minimise this risk:

• Make sure you are fit to drive. Do not begin a journey if you are tired. Get a good night’s sleep before embarking on a long journey
• Avoid undertaking long journeys between midnight and 6am, when natural alertness is at a minimum
• Plan your journey to take sufficient breaks. A minimum break of at least 15 minutes  after every two hours of driving is recommended
• If you feel sleepy, stop in a safe place. Do not stop on the hard shoulder of a Motorway
• The most effective ways to counter sleepiness are to drink, for example, two cups of caffeinated coffee and to take a short nap (up to 15 minutes)*

Drivers that press on, following the onset of fatigue, often try in vain the put the situation right. Most of the measures that they employ to keep themselves awake/alert, simply don’t work.

An emergency* measure is to find somewhere safe to stop, take two caffeine drinks, and have a nap for at least 15 minutes to help to reduce sleepiness. These measures can only ever be a temporary solution, as sleepiness will return if the driver does not stop driving quite quickly afterwards.

As always, the safest option is for drivers to avoid driving when tired.

The problem of driver fatigue can affect any of us, so be on your guard.