SAN ANTONIO, Texas A new study suggests that motorcoach companies and others looking to hire veterans returning from Iraq and Afghanistan as drivers need to proceed cautiously.

U.S. military personnel have 13 percent more car accidents in which they are at fault in the six months after returning from overseas duty than in the six months prior, a study by USAA reveals.

USAA, a major insurer that specializes in insuring members of the armed forces and their families, based its study on 171,000 deployments by 158,000 of its members over a three-year period ending in February 2010, when combat operations were still under way in both Iraq and Afghanistan.

In many cases, USAA found, soldiers took the driving style that kept them alive on the streets of Baghdad and Kabul and applied it to suburban roads at home.

The results were most dramatic for returning members of the Army and Marines, whose accident rates rose 23 percent and 12.5 percent, respectively. (Rates were up 3 percent for the Navy and 2 percent for the Air Force.)

Not surprisingly, given the experience many soldiers had with improvised explosive devices and other roadside obstacles in combat zones, USAA found "objects in the road" to be the most cited of the 13 accident causes it studied.

The insurer also found a direct correlation between the number of deployments and the rate of accidents - those deployed three or more times had 36 percent more incidents, those deployed twice had 27 percent more and those deployed only once had 12 percent more accidents.

A 2009 military study found that, since 2001, deployments for reservists had averaged from 8 to 14 months in duration.

There also was a correlation by age (soldiers under 22 were involved in more wrecks than those over 29) and by rank (the more senior a soldier the lower the number of accidents).

One motorcoach industry executive who examined the USAA report said that while operators shouldnt be dissuaded from hiring a qualified veteran, the report suggests that anyone hiring veterans as drivers should make sure those individuals receive "good training and even better supervision."

USAA said it has shared its research with each military branchs safety center commanders. USAA also shared the study with academics and traffic safety experts and has taken steps to make USAA members aware of the behind-the-wheel risks for returning troops.

The company had 8.8 million insured individuals as of the end of 2011.

The USAA survey adds to the growing body of data on the psychological and physical effects of deployment to war zones.