The human body's circadian rhythms make it particularly hard to stay alert between 2 and 6 a.m., and even at 7 or 8 a.m. When you put these factors together, it's easy to see why many people who work the overnight shift have had at least one frightening experience of nodding off at the wheel. Get enough sleep. A safe drive home begins well before you ease yourself into the driver's seat as the sun comes up. To avoid attention lapses on the road, you need to get enough sleep.
Most people require seven or eight hours of sleep a day to function well.
If you can't sleep a full eight hours at one stretch, then supplement your main sleep period with naps. Be aware of the accident risk. Recognize that you can fall asleep at the wheel. You need to be conscious of the three risk factors discussed above. For example, if you only got three hours of sleep yesterday and you didn't have a chance to take an afternoon nap, an alarm should go off in your head warning you that you're at higher risk than usual.