Facts you should know about excessive sleepiness or tiredness and driving
There is no excuse for falling asleep at the wheel and it is not an excuse in law.
• Up to one fifth of accidents on motorways and other monotonous types of roads may be caused by drivers falling asleep at the wheel.
• 18 to 30 year old males are more likely to fall asleep at the wheel when driving late at night.
• Modern life styles such as early morning starts, shift work, late and night socialising, often lead to excessive tiredness by interfering with adequate rest.
• Drivers who fall asleep at the wheel usually have a degree of warning.
• Natural sleepiness or tiredness occurs after eating a large meal.
• Changes in body rhythm produce a natural increased tendency to sleep at two parts of the day: Midnight to 6am and 2pm to 4pm.
• Although no one should drink and drive at any time, alcohol consumed in the afternoon may be twice as potent in terms of producing sleepiness and driving impairment as the same amount taken in the evening.
• Prescribed or over-the-counter medication can cause sleepiness as a side effect, always check the label if you intend to drive.
Medical conditions causing sleepiness
All drivers are subject to the pressures of modern life, but many drivers are unaware that some medical conditions also cause excessive sleepiness or tiredness. These, alone or in combination with the factors mentioned previously, may be sufficient to make driving unsafe. A road traffic accident may
be the first clear indication of such a sleep disorder. If you know you have uncontrolled sleepiness you MUST not drive.
Obstructive Sleep Apnoea (OSA) and Obstructive Sleep Apnoea Syndrome (OSAS)
OSAS is a condition which often goes undiagnosed. If it is not fully assessed and treated, this can cause sleepiness and other symptoms which can be a serious risk factor in road traffic accidents. For further details about how to recognise symptoms go to www.gov.uk/obstructivesleep-apnoea-and-driving
You must tell us immediately if you are diagnosed with OSAS.
• OSAS is the most common sleep-related medical disorder.
• OSAS increases the chances of a vehicle crash by about five times.
• OSAS occurs most commonly, but not exclusively, in overweight individuals.
• Partners often complain about snoring and notice that the sufferers have breathing pauses during sleep.
• OSAS sufferers rarely wake from sleep feeling fully refreshed and tend to fall asleep easily when relaxing.
• Long distance lorry and bus drivers affected by OSAS are of great concern as most will be driving on motorway type of roads and the size or nature of the
vehicle gives little room for error.
• Sleep apnoea affects on average about 25% of men and 10% of women.
• OSAS affects on average 4% of men and 2% of women.
•Sleep problems arise more commonly in older people.
• Lifestyle changes, for example weight loss or cutting back on alcohol, will help ease the symptoms of OSA.
• The most widely effective treatment for OSAS is Continuous Positive Airway Pressure (CPAP), this requires the patient to wear a soft face mask during
sleep to regulate breathing. This treatment enables patients to have a good night’s sleep, so reducing daytime sleepiness and improving concentration.
Other sleep related conditions
Illnesses of the nervous system, such as Parkinson’s disease, multiple sclerosis (MS), motor neurone disease (MND) and narcolepsy may also cause excessive sleepiness or fatigue although sometimes these illnesses alone may cause drivers to be unfit for driving.
Tiredness or excessive sleepiness can be a non-specific symptom of Parkinson’s disease, MS, MND or may also be related to prescribed medication.
Narcolepsy also causes daytime sleepiness and tiredness as well as other symptoms that may be disabling for drivers.