SREL Reprint #3725

Driving in the dark: Deciphering nighttime driver detection of free-ranging roadside wildlife

Carson J. Pakula1,2, Shane Guenin1,2, Jonathon Skaggs1, Olin E. Rhodes Jr.1,3, and Travis L. DeVault1

1Savannah River Ecology Laboratory, University of Georgia, P.O. Drawer E, Aiken, SC 29802, USA
2Warnell School of Forestry and Natural Resources, University of Georgia, 180 E Green St,
Athens, GA 30602, USA
3Odum School of Ecology, University of Georgia, 140 E Green St, Athens, GA 30602, USA

Abstract: Wildlife-vehicle collisions are dangerous for motorists; however, few studies have addressed driver detection of roadside animals, and none have evaluated detection of free-ranging wildlife. We used 24 volunteer drivers, infrared videography, a 75-km route, and free-ranging wildlife to quantify factors influencing (1) probability of wildlife detection, (2) detection distance, and (3) probability of dangerous encounters (i.e., detection distance < distance required for braking) for multiple species at night in South Carolina, USA. Detection probability of white-tailed deer (Odocoileus virginianus) was impacted by multiple driver, animal, and roadside factors. Deer detection distances increased by 20.99 m when drivers used high-beam headlights and 23.36 m when deer were moving but decreased by 0.71 m for every minute into a drive. Every encounter with wild pigs (Sus scrofa) and most encounters with small mammals were considered dangerous. Our findings suggest most drivers cannot safely detect deer, wild pigs, and small mammals at night.

Keywords: Wildlife-vehicle collisions; Road ecology; Headlights; Detection distance; White-tailed deer (Odocoileus virginianus); Wild pigs (Sus scrofa)

SREL Reprint #3725

Pakula, C., S. Guenin, J. Skaggs, O. E. Rhodes Jr., and T. DeVault. 2023. Driving in the dark: Deciphering nighttime driver detection of free-ranging roadside wildlife. Transportation Research Part D 122: 103873.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).