Motorists falling asleep behind the wheel are believed to cause about 20% of all road accidents.

DRIVER fatigue is a constant headline grabber, and no wonder. Drivers nodding off behind the wheel are responsible for more deaths on UK roads than accidents caused by drink-drivers.

With driver sleepiness believed to cause about 20% of all accidents it is an issue which should be at the forefront of every fleet manager's agenda.

That an accident is caused by the driver falling asleep is obvious. But what are the signs of tiredness drivers should look out for and how can they combat varying levels of fatigue?

Speaking at a recent road safety conference, Hugh Brogan, responsible for group training at Rathbones Bakery, urged fleet managers to be aware of the differences between driver fatigue and driver sleepiness.

He said: 'Drivers should be aware of the differences. Fatigue is when your body is tired, which can be overcome by going for a walk or having a break. But driver sleepiness is a more serious problem.'

Studies from the Loughborough Sleep Research Centre (LSRC), which has completed several studies on the processes of falling asleep at the wheel and methods of overcoming it, have shown that sleep loss prevents drivers from making snap decisions.

A report from the centre states: 'Sleep loss may well impair the ability to fully comprehend a rapidly changing situation, leaving a driver liable to be distracted by irrelevant information, think more rigidly and be less able to produce innovative solutions.'

However, this can be overcome for a limited period according to the LSRC. It suggests that one can of an energy drink such as Red Bull can reduce moderate levels of sleepiness, with two cans eliminating the levels of sleepiness for 90 minutes after the drink has taken effect.

It suggests drivers should have two cans of energy drink or approximately 180mg of caffeine followed by a 15-minute nap. This should combat short-term tiredness but is not a permanent solution.

Simon Elstow, manager of the Drive & Survive Academy, the fleet driver training centre, said that there are several reasons why people get tired which then goes on to affect their behaviour.

This includes the monotony of motorway driving. It is a key factor in driver sleepiness as drivers tend to stare at the same horizon.

Elstow said: 'The term most commonly used to describe the type of boredom-induced sleep on motorways is highway hypnosis. This appears to bear an uncanny resemblance to the well-researched condition of empty field myopia. 'This condition is what affects pilots where the lack of points of reference result in the pilots' resting vision being around three metres in front of his cockpit.

'The technique advised for combating highway hypnosis is, first, to stop in a safe place. Secondly, have a functional energy drink, followed by a 15-minute nap.'

Drivers should also keep refocusing, looking near and far to stop this happening. Rear-end shunt accidents are common on motorways, with sleepy drivers being a main cause. Elstow added: 'Drivers tend to stare into the distance for too long on motorways. When the vision is bought back to the vehicle in front, they tend to mirror that vehicle.

'If the vehicle pulls up to the back of a queue without using his brakes, the tired driver will drive straight into the back of the queue. Brake lights usually act as a trigger then to alert the driver.'

Another common problem is drivers closing their eyes for a few seconds and making a vital error on opening them.

Elstow said: 'Imagine a multi-lane environment, where the tired driver is in lane one, following a car. The driver closes his eyes for just two seconds. In the meantime, the car in front has a problem and indicates into the hard shoulder. On opening his eyes, the driver sees an empty lane and presumes he has moved into the middle lane, so quickly pulls onto the hard shoulder, thinking it is lane one, causing an accident.'

As fleet drivers often travel the same routes, the risk of highway hypnosis and tiredness puts them in a higher risk category. Males are also at more risk. Studies from the Department for Transport (DfT) have shown that men aged 30 or under are more likely to have a sleep-related accident than any other age or gender.

There are indicators forewarning extreme tiredness, such as touching the face. Drivers who feel tired will usually find themselves winding down the window for cold air, turning up the radio or stretching at the wheel, all indications that it is time for a break. Drivers should take regular two-hourly breaks to prevent tiredness, according to the DfT.

Elstow recommends 'commentary driving' as another remedy for tiredness. 'Talk about what you can see around you as you go along,' he said.

If the worst happens and the driver does fall asleep at the wheel, they will be unlikely to have any memory of the 30 minutes prior to the accident.

Another indication that a driver has nodded off is that there will be no skid marks at the scene of the accident.

Government and industry risk accident adviser Awake provides driver fatigue assessments for fleets concerned about the risks of drivers falling asleep at the wheel. The group looks at shift patterns to determine peak tiredness levels, analyses accident rates and interviews drivers to determine individual risk.

Fleet decision-makers must make staff aware of driver fatigue, including prevention, symptoms and the consequences of falling asleep at the wheel.

Road accident fact file

  • 40,000 serious injuries and nearly 3,500 deaths occurred on UK roads last year, with drowsiness thought to be a major cause
  • Road accidents relating to sleep occur at higher speeds as the driver fails to break as he or she is asleep
  • Each road death costs about £1 million
  • Most accidents happen between 2am and 6am and 2pm and 4pm
  • Falling asleep at the wheel is preceded by feelings of extreme sleepiness that drivers tend to ignore
  • Males aged between 18 to 30 years-old are responsible for more than 50% of sleep-related accidents Source: Loughborough Sleep Research Centre

    Karolinska sleepiness scale
    The Karolinska sleepiness scale is used to determine levels of tiredness and shows the different stages of fatigue. When drivers begin to see 'some signs of sleepiness', they need to remedy the situation according to Elstow.

    He said: 'Number six on the Karolinska scale is where it gets interesting. The 'blink question' is the sign where stopping is necessary. The test is simply to ask yourself, 'How long will the next blink last?

    'The blink under consideration is the sleep-induced variety as opposed to the irritation sort. The problem is that in reality many drivers have already passed the point where they can recognise the difference.

    The scale, with one being safe and nine being dangerous, is:
    1. Extremely alert
    2. Very alert
    3. Alert
    4. Rather alert
    5. Neither alert nor sleepy
    6. Some signs of sleepiness
    7. Sleepy, no effort to stay awake
    8. Sleepy, some effort to stay awake
    9. Very sleepy, great effort to stay awake