The behavior includes driving fast or down the middle of the road, or passing through intersections regardless of signals, say the study's authors, who are releasing results today.
"These behaviors become both automatic and inexorably linked to a sense of control and safety," says the study by sociologist Todd Rockwood and occupational therapist Erica Stern of the University of Minnesota.
"Unfortunately, when these same driving behaviors are inappropriately carried over to American roads, they endanger soldiers, their families and their communities," the study said.
The team surveyed 150 members of the Minnesota National Guard who had served in Iraq and Afghanistan. As a result of the findings, the Pentagon is paying to expand the study to survey 600 more troops, say Rockwood and Navy Capt. E. Melissa Kaime, director of the Defense Department's Congressionally Directed Medical Research Programs.
The Minnesota researchers found that during a 30-day period in 2007, 25% of the combat veterans admitted driving down the middle of a civilian street or running a stop sign. Ten percent said they drove erratically through an underpass or tunnel.
Much of this behavior seemed to diminish 90 days after soldiers returned home, Rockwood said.
But the soldiers remained apprehensive about driving even beyond 90 days, researchers found. Nearly half said they were uneasy when they felt boxed in by traffic, the study results say.
Kaime says the Pentagon wants to learn more.
"Can we somehow identify, predict who is likely to come back with the most erratic driving behavior?" she asked. This would help the military provide assistance to those most at risk, she says.
Fatal accidents involving soldiers increased after the wars in Iraq and Afghanistan began, peaking in 2005, according to statistics.
They have since declined after aggressive Army efforts to monitor soldiers' driving behavior and educate them.