An estimated 1.5 million deer-vehicle collisions occur annually in the U.S., resulting in damages of about $1 billion, according to a Texas AgriLife Extension Service wildlife specialist.

And deer aren't the only large mammal apt to cross against traffic. Research has shown feral hog-vehicle collisions may occur at an average rate of about 1 percent of the hog population or more yearly, said Dr. Billy Higginbotham, AgriLife Extension wildlife specialist.

"This means an estimated 10,000 hog-vehicle collisions for each one million hogs," he said.

Though there have been "guess-timates" published on the number of feral hogs in Texas, no one really knows how many there are, Higginbotham said.

"If anyone quotes you a number, then they're lying, because it's all conjecture," he said.