For veterans and those who have observed the Iraq and Afghanistan wars, one of the most enduring images is of military caravans being attacked by roadside bombs. The terms "improvised explosive device," or IED, is now part of our national lexicon. Thousands of troops who endured IED attacks while deployed later came back suffering from post-traumatic stress disorder, or PTSD.

Symptoms of PTSD can include panic attacks and perception of danger where none exists. That may partly explain a study by USAA, an insurance company that specializes in active-duty and retired servicemembers, which found that car accidents in which an active-duty servicemember was at fault rose 13 percent after the soldiers came back from deployment. Army figures indicate that 48 off-duty soldiers died in accidents in 2011, the most in three years.

Veterans of previous wars like Vietnam and the Gulf War have been found in previous studies to be more likely to die in accidents than non-deployed veterans, but experts say the current generation of veterans is unique because they had to deal with IEDs, which often left them tense and anxious behind the wheel once they return to civilian life. As a result, they sometimes drive aggressively, raising the risk of a serious crash. A study of National Guard soldiers who served in Iraq in 2007 found that about 25 percent of those surveyed admitted to running a stop sign, and a third of the soldiers had been told they are dangerous drivers.

Even when PTSD is not a factor, veterans may be driving overly aggressively due to their training. One Palo Alto, California veteran of the Iraq War found herself driving down the center of the street, as she had been trained to, and avoiding cramped parking lots if there was no easy escape route.

Source: The New York Times, "Back From War, Fear and Danger Fill Driver's Seat," James Dao, Jan. 10, 2012