When tiredness becomes dangerous

Your alertness level is reduced

When driving makes you tired, it affects your ability to drive safely. Your reactions are impaired, so it takes you longer to see, assess and so react to anything unexpected. Your alertness level is reduced and you can overlook signals from your surroundings such as warning signs for sharp bends and roadworks.

2-3 seconds can be fatal

In extreme cases, there is a risk of you falling asleep for short periods, known as "microsleep". If you doze off for just two or three seconds on a motorway, you could cover the length of a football pitch before you wake up again! And into the bargain, tiredness-related accidents are more serious, on average, than other road traffic accidents as they often involve high speeds and drivers are unable to take evasive action.

Increasing the risk of tiredness when driving

Tiredness when driving develops over time when you drive. The further you drive, the greater the risk of your alertness level and your ability to react being reduced. Even if you are well rested and feel wide awake when you set off, the monotony of driving for any length of time will often cause tiredness when driving.

There are also numerous factors which increase the risk of tiredness when driving:

• Lack of sleep. The risk increases markedly if you have not had enough sleep. And this applies even after just one night in which you have had less sleep than usual. Be aware that one night is not enough time to catch up on lost sleep.
• Sleep quality. The quality of your sleep also has an influence on the risk of tiredness when driving. Shift work, loud snoring, young children, insomnia, noise, heat, etc. can all cause poor sleep quality.
• Physical fatigue. Physical fatigue may be a result of you having done particularly hard physical work or a lot of exercise, or otherwise having exerted your body prior to driving. Your biological clock will also react to irregularities – if you drive at night, for example, you will have a natural tendency to feel sleepy.
• Mental fatigue. Mental fatigue can be caused to situations in your life which demand a lot of attention and so stop you focusing on other things, such as driving your car.

You often underestimate your own tiredness when driving

The only effective solution to tiredness when driving is to take a break before you reach a critical level. The problem is that it is very difficult to work out for yourself when you have reached this level. There can be a long time between you needing a break and you admitting it to yourself, and then to actually having that break. In the interim, the risk of accidents involved in driving when tired is increased.

We can all experience driving fatigue, but some kinds of people are more susceptible

Everyone is different, including when it comes to the risk of being involved in an accident caused by driving when tired. When causes of accidents are investigated, it is apparent that some people are at particularly high risk. These are:

1. Young drivers (aged 18-25)
2. Shift workers with changing sleep patterns
3. People with sleep problems – including sleep apnoea

Even if you do not belong to any of these groups, you should always watch out for the signs of driver fatigue. Driving when tired can affect anyone – simply because of the often monotonous nature of driving and the duration of journeys. How and when are very much dependent on who you are and how tired you are before you start driving.

To learn more about your personal risk profile and get tips on how you can drive more safely, go to Test yourself. 

Increasing global awareness

The problem of driving and fatigue has gained increasing attention and a status as a major social issue in a many countries. This is expressed in particular in campaigns, government-funded studies, and considerable scientific activity on the subject as well as in legislation. In many countries the laws and courtroom trials state that it is punishable by imprisonment to cause accidents when the driver is suffering from severe fatigue.

For further information you can check these links:

• Organisations and reports dealing with the problem in Want to know more?

• Traditional and social media coverage of the topic in Media focus