Being in a state of fatigue is more than feeling sleepy; it is a state of extreme tiredness, resulting from mental and/or physical exertion or illness. Fatigue ranks as a major cause of road crashes. Driver fatigue is particularly dangerous as a major symptom is decreased ability to judge one's level of tiredness.
There are a range of factors that may cause fatigue. Common causes include:
LACK OF QUALITY SLEEP: Working for long hours without adequate sleep will increase risk of fatigue while driving. Lack of sleep may also be due to sleeping disorders such as sleep apnea or insomnia.
TIME OF DAY: Driving when your body feels sleepy (e.g. 1am-6am at night or in the hours between 2pm-4pm when your biological clock makes you feel tired).
DURATION SPENT ON THE TASK: Fatigue may occur when you spend long hours behind the wheel. This is particularly true for professional drivers who work on cross-country routes or shuttles.
The following are telling signs that you are tired and you should stop driving if you notice the following:
• Sore eyes
• Constant yawning
• Drifting between lanes
• Trouble keeping your head upright
• Delayed reactions
• Difficulty remembering the last few kilometers on the drive
• Variations in driving speed.
Here are a few helpful tips to avoiding driver fatigue:
• Get enough sleep. Before you begin driving, especially for a long trip, be sure to have 7 to 8 hours of uninterrupted sleep.
• Time yourself. As much as possible, avoid starting a trip immediately after work; you will be tired already, even though you do not realize it. Also, do not drive for more than 8 to 10 hours each day.
• Share the driving. If possible, travel with at least one companion who can take over the driving when you're tired. Get your passengers to tell you if you show any signs of tiredness while you drive.
• Eat well balanced meals at your usual meal times. Avoid fatty foods which can make you feel drowsy.
• Avoid alcohol and medicines that can cause drowsiness.
Most importantly, if you feel tired, pull over and have a power nap. Otherwise, you may experience micro sleep which is dangerous while driving. Micro sleep refers to unintended periods of light sleep that last a few seconds or several minutes. Once you are fatigued, the most practical cure is to stop and take a break.