Sleep Disorders and driving when tired
Up to one fifth of accidents on motorways and other monotonous roads may be caused by drivers falling asleep at the wheel.
Driver sleepiness may be caused by modern lifestyles preventing people getting enough rest. It may be made worse by shift working, especially if combined with the monotonous nature of certain types of driving.
Alertness fluctuates naturally throughout the day. Driving between 2am and 7am increases the risk of a sleep related accident. Most people also tend to be less alert during the mid-afternoon or after a heavy meal.
All drivers need to address these problems responsibly, but drivers of heavy goods vehicles and passenger carrying vehicles need to be extra vigilant because they tend to spend more time driving and to drive longer distances than other drivers. Also, accidents involving these large vehicles are more likely to result in death or serious injury than those involving cars or smaller vehicles. A number of recent fatal road accidents and coroners’ inquests have highlighted this risk.
In addition to lack of adequate rest, some medical conditions may cause excessive sleepiness. These will greatly increase any normal tendency to sleepiness. The most common medical cause for excessive sleepiness is Obstructive Sleep Apnoea Syndrome (OSA).
Am I at Risk?
OSA occurs most commonly, but not exclusively, in overweight individuals, particularly those with a large neck size. It can also be associated with diabetes and some other medical disorders.
What to look out for.
Sufferers of OSA rarely wake from sleep feeling fully refreshed; they also tend to fall asleep easily when relaxing. Their partners often complain about snoring and notice that sufferers seem to have irregular breathing during sleep. Chronically sleep-deprived individuals may feel constantly tired and below par and this can occur even if they appear to be getting 6 or 7 hours sleep.
What causes OSA
OSA is caused by the airways at the back of the throat becoming partially closed off during sleep. The sleeping individual breathes more and more heavily and with increasing difficulty, often accompanied by loud snoring. When breathing becomes almost impossible, the person begins to choke and wake up; waking activates the throat muscles and opens the airways so that breathing can begin again. The person drifts back to sleep only for the same pattern of interrupted breathing – and interrupted sleep - to recur over and over again throughout the night. So, it is not just the apparent duration of sleep that is important but the quality of sleep. Those who suffer from OSA will finally awake feeling drained and un-refreshed, because they have half-woken maybe 20 or 30 times per hour during the night.
Not only does OSA cause daytime sleepiness but it can carry increased health risks to the person as well, particularly of high blood pressure and heart conditions.
Treatment….and Driving Fitness
A driver with undiagnosed and untreated OSA is a significant risk to themselves and others on the roads because of the increased tendency to fall asleep easily when driving. All drivers have a responsibility to ensure they are fit to drive behind the wheel but drivers with untreated OSA may not understand quite how chronically sleepy they are; many will have forgotten what it feels like to feel alert! Untreated OSA is not compatible with safe driving.
Once OSA is diagnosed, however, there is very effective treatment available. This is usually given in the form of a breathing mask (called CPAP) which can even be used in the cab when sleeping during overnight lorry stops. The greatest road safety danger in a driver is before the diagnosis is made, when the importance of the sleepiness symptoms is not appreciated. A road traffic accident may be the first clear indication that the driver has OSA. If you think that you may be suffering with OSA, don’t wait for an accident to happen; please seek the advice of a medical practitioner. You may wish to mention that you feel you have the symptoms of OSA and, where appropriate, remind the doctor that you are a professional driver.
DVLA’s licensing rules.
All drivers must, by law, inform DVLA if they develop a medical condition, including sleep disorders such as OSA, which may affect their ability to drive safely. Once DVLA is informed, medical enquiries are undertaken to establish whether the driver should retain their licence. In the case of OSA, drivers should be reassured that driving will normally be allowed to continue once satisfactory control of the condition is achieved. Generally, satisfactory control can be achieved very quickly, within a week or two and most people comment on how much better and more refreshed they feel once treatment is established. Drivers with this condition should not drive until good control is established and this has been confirmed by their doctors; there may be insurance implications in the event of a crash if unfit drivers drive against medical advice.
Information on the medical standards for drivers, including those required for professional drivers, are published in a booklet, “At a Glance Guide to the current Medical Standards of Fitness to Drive”, which is available for download in PDF format http://www.dvla.gov.uk/medical/ataglance.aspx The booklet is aimed at doctors; individual drivers should discuss with their own doctor how its guidance might apply to their particular condition or situation.
An information leaflet “Think! Tiredness can kill: Advice for drivers”, linked to the Department for Transport “Think!” campaign is also available to any driver who has concerns about driving whilst tired. This leaflet is also distributed to sleep disorder clinics on request and is available to download from the Medical Rules for Drivers section: www.direct.gov.uk/en/Motoring/DriverLicensing/MedicalRulesForDrivers/index.htm
If a driver has any queries regarding their case, or is not sure whether they need to
inform DVLA of a medical condition, they can ring the Drivers Medical Enquiry line on 0870 6000 301.
Further advice:
Brake Fleet Forum.
RoSPA