Soldiers returning from active duty overseas have more than a few hurdles to jump as they settle back into life outside of a combat zone. According to a recent study, it can take months for service members coming home from Iraq and Afghanistan to adjust to driving stateside. The study showed that military personnel are responsible for 13 percent more accidents after they get home than they were before they left.

What makes the results so interesting is that the accidents are not caused by the carelessness of the drivers. The explanation is both more obvious and more subtle: The roads of Portland are different from the roads in war zones. It’s not carelessness that causes the crashes. It’s caution.

The wars in Iraq and Afghanistan have become well-known for roadside bombs and improvised explosive devices. The roads are literal mine fields, and military personnel adopt driving styles that protect them and their passengers. The most commonly cited reason for accidents back in the U.S. was “objects in the road.” It takes time to adjust to the relatively mild hazard posed by a Big Wheel at the curb.

The study came from USAA, an insurance company that specializes in covering military service members and their families. The researchers looked at car accident data from the six months before deployment and the six months following the return home of 158,000 of USAA’s military policyholders. Over the three-year study period, those policyholders logged 171,000 deployments. An assignment to a combat zone can last a year or more.

The results varied for the different military services. The highest increase was the Army’s 23 percent increase; members of the Marine Corps registered a 12.5 percent hike in the number of accidents. Far less dramatic were the increased accident rates for members of the Navy (up 3 percent) and Air Force (2 percent). Personnel from those branches were less likely to have been on the ground, much less behind the wheel in combat zones.

The study also found that more deployments were directly tied to higher accident rates. Only 12 percent more accidents were experienced by returning service members deployed only once, while the rate more than doubled to 27 percent for those with two deployments, and tripled to 36 percent after three or more deployments. Younger soldiers (under age 22) had more accidents than those over age 29, while more senior soldiers had fewer accidents than those of lower rank.

Source: Reuters, “Returning soldiers have more car crashes: study,” Ben Berkowitz, April 24, 2012