The latest cause of dangerous driving to be getting attention is drowsiness or falling asleep at the wheel.

"The U.S. National Highway Traffic Safety Administration estimates that 100,000 of reported crashes occur as a result of drowsiness, and considers sleep deprived drivers a hazard equal in severity to drunk drivers," according to safety.com.

It cites studies showing studies that "staying awake for 18 hours and driving produces the same effect as being legally drunk behind the wheel."

In other words, poor concentration, slower reaction time, increased irritability and impaired judgment, according to the Sleep Care Center at Robert Wood Hospital, Hamilton, N.J.

However, it is hard to correlate numbers on the role that fatigue might have played in an accident, although annual costs have been estimated at $12.5 billion.

So far, New Jersey is the only state to enact legislation regarding the dangers of driving while drowsy. A driver who causes an accident after being awake for 24 hours can be charged with vehicular homicide.

Safety.com said Farmer's Insurance found that 10 percent of drivers admitted to falling asleep at the wheel and 20 percent admitted to momentarily dozing off.

Frankly, that sounds low to me. Indeed, I'd wager nearly all of us have been aware of being tired while driving at one time or another.

Pulling off the road and taking a nap is an option. But it you are a few miles from home, the tendency is to sit up, open the windows and crank the radio up.

And keep driving.

But given that a car traveling at 55 mph covers 160 feet in 2 seconds, it does not take much imagination to see how dangerous nodding off can be.

Combine that with the insidious nature of fatigue - how do we recognize the difference between being tired and being too tired? - and the dangers are even more evident.

Such knowledge comes from experience and self awareness - much as we learn to be able to moderate our drinking, to know when we have had enough and when we've had too much.

(I like that old saw that advises that one drink is just right, two drinks are too many and three drinks are not enough.)

Certainly I can remember taking my own tiredness to the limit in my teenage years while a student in France. After spending far too much time on the road, I took the ferry to England and tried to drive home at the dead of night, only to end up in a ditch courtesy of extreme fatigue.

If nothing else, it taught me my limits but the price could have been much higher.

- Peter C.T. Elsworth