Why a tired driver is as dangerous as a drink driver
Our Road Safety Authority expert this week warns about the risk of feeling sleepy at the wheel – and has an eye-opener of a suggestion
Published 07/05/2014 | 02:30
A friend was telling me about an experience he was having more and more regularly on the commute home. He couldn't remember anything about parts of his drive. He reckoned it was because he was tired and obviously had tuned out mentally. He was half right.
Research suggests that not remembering stretches of a journey just driven is not really anything to do with being a tired driver. It's more a case of distraction caused by driving on familiar roads. Driving the same route every day, the brain is simply not stimulated enough. There is even a scientific name for it – 'familiar route syndrome'. I wonder how much of a factor this is in crashes that happen at the time of the daily commute?
The two biggest spikes in collisions each day, looking at crashes to date this year, happen in the morning (18pc) and evening rush hour (20pc). It might also explain why collisions tend to happen closer to home. Familiarity breeds contempt?
Driving while tired is a whole other road safety problem. Ideally, everyone needs seven to eight hours of sleep each night. If you don't, you end up with a sleep debt and you can't get rid of it by 'banking' sleep at the weekend. Drivers with a 'sleep debt' are at risk of nodding off while driving and substantially increasing their risk of being involved in a crash.
But people don't just suddenly fall asleep at the wheel. It is a gradual process. If you didn't get a good night's sleep, you know there's a good chance you will feel tired at the wheel.
Many react to feeling tired by using tactics such as turning up the volume on the radio or opening the window. They don't work.
The best one I've heard was the driver who trapped her hair in a sun roof so that if she nodded off she would be jolted awake.
Or the driver who put an elastic band with thumbtacks around his wrist, hoping the pain would keep him awake. Extreme? Yes. Effective? No.
If you do find yourself yawning, sleepy or fighting sleep at the wheel, that's your brain trying to send you signals. You are tired. If a driver is suffering from a serious lack of sleep, they should not drive.
The only cure for a lack of sleep is sleep.
If a driver fights sleep while driving, the impairment level is the same as driving while drunk.
Eventually a driver will drift in and out of consciousness and will experience 'micro sleeps' which can last for up to 10 seconds. Drivers can have a micro sleep with their eyes wide open. If a driver has a micro sleep for just four seconds while travelling at a speed of 100kmh the car will have travelled the length of eight buses without a driver in control or even realising it is happening.
Fatigue crashes are more likely to occur on straight open roads such as motorways. Night workers coming off shift and driving home are a high-risk group. So too are truck and long-distance drivers. Those suffering from sleep disorders such as sleep apnoea and insomnia are also in the high-risk category.
The advice for drivers suffering from fatigue and who find themselves fighting sleep at the wheel is to use common sense and listen to the signals your body is sending. Stop driving. Take a 15-20 minute nap. If you can, take a caffeine drink just before the nap. The caffeine takes about 20-30 minutes to take effect. After the nap, take some fresh air. By the time you restart your journey, the caffeine should have taken effect.
By taking a nap and drinking caffeine you should be able to drive for another one to two hours. Drinking caffeine alone should enable a driver to drive for another half hour to one hour. Obviously these times will vary depending on just how sleepy a driver is and in cases of extreme tiredness brought on by sleep deprivation, the only cure is sleep.