With this week's apparent suicide involving a person stepping into or lying down in traffic -- the third in nine weeks -- the State Patrol has some blunt counsel for drivers unwittingly being used as weapons.

"It's incredibly difficult to avoid as a motorist because it's really out of your control," said patrol spokesman Lt. Eric Roeske. "If you find yourself in that situation, as selfish as it may seem, the most important thing you can do is maintain control of your vehicle and not bring harm to yourself through a sudden movement or overcorrection."

Tuesday's fatality occurred when a man parked his car on the side of Interstate 694 in White Bear Lake and lay down in the road, where he was struck and killed by a semitrailer truck. On Dec. 22, a man died after walking into oncoming traffic on Interstate 35E in Hugo and being hit by a semi and an SUV. On Nov. 18 in Minneapolis, a woman who lay down on Interstate 94 died after being hit by several vehicles.

While careful not to call the incidents an epidemic, Roeske said their quick succession "does seem a bit over the norm."

Suicide-by-motorist is rare, said Alan Berman, executive director of the American Association of Suicidology in Washington, D.C., although adding that "for you to have three in that period of time, that's unusual."

Some copycat behavior could be involved, he said, but you'd have to prove that the person was aware of previous incidents. In any case, innocent drivers, in a matter of seconds, will have their lives upended.

"The reality is that the motorist in this sort of incident is thrust intentionally into it ... and to be involved in the death of another person is going to be traumatizing," Berman said.

Statistics aren't kept for this particular method of suicide. In 2007, suicide accounted for about 34,600 deaths nationwide, according to the Centers for Disease Control. Of those, Berman said, 104 involved motor vehicles, but that also includes deaths in which the driver was the suicidal person.

Studies by the Transportation Research Institute at the University of Michigan suggest that 2 to 3 percent of fatal truck crashes involve such suicides. Of the 3,675 truck-related fatalities in 2010 nationwide, perhaps 75 to 100 involved suicides.

Rob Abbott, vice president of safety for the American Trucking Associations, said truckers worry because their vehicles are most likely to result in a fatal injury. "It's tragic for all -- for our drivers as well as the person who feels driven to this," he said.

Kim Ode • 612-673-7185