03/19/2011 05:50 pm ET | Updated Nov 17, 2011

Driver Fatigue Brought to Light in NYC Bus Crash Investigation

The tragic bus accident that killed 15 people after it violently crashed on I-95 just outside of the Bronx last week has raised multiple questions for federal investigators. Among the causes being investigated by the National Transportation Safety Board was whether the bus driver was so fatigued he was not capable of driving properly. To determine that, they will be checking surveillance video and room records at Mohegan Sun where the bus traveling from, carrying people back to New York City's China Town.

Although there are numerous questions as to why the driver, a convicted felon, should have even been behind the wheel of the bus in the first place, there is no question that even if fatigue wasn't the cause of this crash, it is a major cause of crashes -- not just for buses, but for trucks, airplanes, trains and boating accidents, as well.

Last fall, the American Automobile Association (AAA) Foundation for Traffic Safety polled 2,000 drivers. One-third of them admitted to either nodding off or completely falling asleep while they were driving in the past year. The results were surprising, indicating the problem is much more profound than previously expected.

More than half of those polled by AAA reported they fell asleep on a high-speed highway. Although it might seem more common to doze off during long car rides, 59 percent said they'd been driving under an hour before they had fallen asleep, and only 20 percent had been driving for more than three hours. 26 percent reported that it happened in the middle of the day, between noon and 5 p.m.

The National Highway Traffic Safety Administration estimates that drowsy driving "results in 1,550 deaths, 71,000 injuries and more than 100,000 accidents each year" and that 57 percent of driving crashes caused by fatigue involved the driver drifting into other lanes or even off the road.

The cause in this growing U.S. problem can be contributed to many factors, not the least of which is the link between daytime fatigue and snoring. Results of a Canadian study published a few years ago linked drivers with sleep apnea with more than double the risk of car and truck accidents. Sleep loss -- whether it is associated with snoring, insomnia or simply poor sleep habits -- impairs a driver's reaction time. It causes people to lose the ability to perform important tasks, impedes memory, reasoning and the ability to learn and perform math. Prolonged sleep loss can also lead to depression and hallucinations, and can cause health problems involving the heart and immune system and be a contributing factor to obesity, which leads to further health issues such as diabetes.

If you're feeling fatigued, it's best to not get behind the wheel at all. The Manhattan Snoring and Sleep Center offers some tips to help stay awake while driving. If you are having trouble getting restful sleep, it is important that you speak to your doctor about it because it is likely more serious that you think.