Dead but not forgotten (Image: Robin Loznak/ZUMApress.com/Corbis)

An estimated 1 million animals are killed by cars each day in the US, costing the nation around $8.4 billion annually. Despite the magnitude of the problem, tracking and analysing those fatalities is difficult. A new app could help.

The app was born out of necessity, says Daniel Olson, a wildlife biologist at Utah State University who took on the task of sorting through all of the state’s roadkill data for his dissertation. Traditionally, state contractors collect such information with old-fashioned pen and paper, and then manually enter it into a digital database. They use mile markers to roughly estimate location, and if a map was needed, they had to import entries into a database. Semi-legible handwriting, lost notes and formatting mix-ups meant frequent errors. “It was my job to make sense of all of it, but it was really hard,” Olson says.

Other groups have developed electronic systems to track roadkill, but those sites and apps require mobile broadband internet – rarely available in rural areas and location entries have to be entered by hand. To increase efficiency and accuracy, Olson and his colleagues designed a smartphone app that seamlessly loads GPS-tagged entries into a central database that can be accessed through a website, both in text and map form.


Olson and his colleagues recruited around 50 state employees to test the app. For one year, the contractors conducted twice-weekly patrols over 1700 miles (about 4 per cent of the state’s roads). They recorded nearly 7000 animals. The app reduced the normal data entry error rate – about 10 per cent – to virtually zero, while location errors decreased by 99 per cent. The increased efficiency also saved around 150 hours of work.

“This is an elegant way of presenting this kind of tool,” says Fraser Shilling, co-director of the Road Ecology Center at the University of California, Davis. “Understanding where these wildlife-vehicle collisions occur allows us to try to prevent them.”

The data recorded by the app can be used to pinpoint the most effective places for building fences or wildlife crossings, Olson says. Or it could be used to design a warning system that alerts drivers when they are entering a wildlife crossing hot zone.

For now, only Utah state workers are using the new app, but Olson hopes to offer it to everyone eventually. “If we want a complete handle on what is happening,” he says, “we’ll need to extend it to citizen scientists.”

Journal reference: PLOS One, DOI: 10.1371/journal.pone.0098613