Millions of animals are killed by oncoming vehicles each year. To understand the problem, U.S. government researchers drove toward the animals in a pickup truck. No mammals, two- or four-legged, were harmed over the course of the study.
By driving toward deer on the road's edge, the scientists found that the animals were frequently slow to react, regardless of the vehicle's speed (which ranged from about 12 mph to a maximum of 55 mph).
Just after nightfall, researchers with the U.S. Animal and Plant Health Inspection Service and the Department of Wildlife drove along roads that cut through suburban deer habitat in Erie County, Ohio. The scientists' Ford F250 pickup truck was outfitted with an infrared camera that could detect deer a half mile away, minimizing the risk to wildlife by making sure each approach toward a roadside animal involved a single deer at a safe distance.
Unlike what the researchers had predicted, the velocity of the approaching truck had little impact on the deers' flight response. Between the springs of 2012 and 2013, the scientists drove toward 67 deer. Three-quarters of the deer fled the truck within 600 feet; on average, the extrapolated "time-to-collision" was only 4.6 seconds.