You've probably read news reports about sleep studies indicating that being sleepy behind the wheel is just as dangerous as being drunk. But is that really true? Is drowsy driving as dangerous as intoxicated driving?

The AAA Foundation for Traffic Safety published a drowsy driving report, claiming that sleep-deprived drivers cause one out of every six fatal motor vehicle accident collisions. This equates to 17 percent of all deadly auto collisions. This statistic may be true, but it doesn't answer the question of whether drunk or sleepy driving is more dangerous. Discovery's Mythbusters television show hosts decided to stay up without sleep for 30 hours to arrive at a more definitive answer.

Before getting drunk and before getting sleepy, the two hosts took driving tests through two obstacle courses while sober and rested. One course simulated city traffic conditions. The other involved 25 laps around a driving track.

In one test, the hosts drove after drinking two shots. In the other test, the hosts drove after skipping sleep for the night. In both cases, being sleepy and being tipsy negatively affected the hosts' vehicle operation skills. They made more mistakes and veered outside of their lanes compared to their sober and rested driving.

Interestingly, the tests showed the driving drowsy was far more dangerous than driving after two shots of alcohol. One host had 10-times worse driving while sleepy compared to tipsy. The other host had 3-times worse driving while sleepy compared to being tipsy.

Sleepy driving isn't exactly illegal, but a driver could be accused of reckless behavior or negligence if authorities prove that he or she was extremely fatigued behind the wheel. Also, some sleepy drivers might get wrongly accused of intoxicated driving by an officer who sees them swerving. In fact, this happens a lot more than you might think. If you were inappropriately accused of drunk driving because you were fatigued or sleepy, you may want to try to defend yourself against your DWI charges in court.