Expand Research Efforts Aimed At Understanding Wildlife Movement Near Corridors, Roadkill Rates, and Road-Barrier Effects and At Developing Efficient Mitigation Designs for Road Crossing by Animals

Focus Area

Wildlife & Ecosystems


Natural Resources







Research Idea Scope

Although crashing into a large animal with a motorized vehicle may involve damage, human injury, or death (Conover et al. 1995; Romin and Bissonette 1996), roadkills overall appear to be a minor problem ecologically. Most animals simply reproduce at a rate that outpaces the losses. The exceptions include flagship species, such as the Florida panther and key deer, and some other statelevel endangered species that probably suffer significant roadkill rates. Perhaps equally important are the many wildlife species whose foraging, dispersal, or migration movements are blocked by roads. These disruptions in natural movement patterns doubtless reverberate widely, affecting the nature of both natural ecosystems and production lands.

Certainly wildlife road-crossing structures capture the public’s imagination (Evink et al. 1999; Clevenger and Waltho 2000). Humble salamander tunnels, “tunnels for toads,” and “tunnels of love” for tiny mountain mammals serve to catalyze aficionados and draw ongoing media attention. Examples include some 30 Florida underpasses that have successfully provided groundwater to Everglades National Park, reduced the roadkill mortality of the threatened Florida panther, restored corridor connectivity for black bear populations, and been used by a wide range of other terrestrial fauna. The impressive wildlife overpasses in Canada’s Banff National Park and in several European nations (with antecedents in New Jersey and Utah) are treasured by the respective national publics. A significant information base exists on the numbers of roadkill, and possible ways of reducing roadkill rates have been the subject of considerable study (Romin and Bissonette 1996).

A limited amount of research is also available on the road as a barrier to movement, including the frequencies of attempted and successful crossing by various animals. Striking research gaps in knowledge also exist, however. For example, how does the arrangement of the surrounding landscape, including wildlife movement corridors, affect where different species tend to cross roads (Evink et al. 1999)? How does road and roadside design affect crossing location? Which species have the highest and lowest road kill rates? And what tunnel, underpass, and overpass designs are most effective and affordable for road crossing by which species (Clevenger and Waltho 2000)?

TERI Administrator Note (January 2009): Research Completed August 2007. See:

FHWA – Wildlife Vehicle Collision Study;

In the recently enacted transportation bill, SAFETEA-LU (Public Law 109-59), the U.S. Congress directed the Secretary of Transportation to conduct a national wildlife-vehicle collision (WVC) study. The Federal Highway Administration’s (FHWA’s) Task Order Proposal Request (TOPR# 68-01-0000) called for a Wildlife Vehicle Collision Study aimed at reviewing methods to reduce collisions between motor vehicles and wildlife. The FHWA selected the Louis Berger Group, Inc. and its partner the Western Transportation Institute at Montana State University (Berger/WTI Team) to complete the Study. The Study will advance the understanding of the causes and impacts of WVCs and solutions to this growing safety problem. Additionally, a report to Congress will document the results of the Study, and the project will result in a best practices manual to guide transportation practitioners in devising the State action plans. Further, the project will develop an accompanying training course. The objective of this research project is to conduct a national wildlife-vehicle collision study aimed at reviewing the methods to reduce collisions between motor vehicles and wildlife.

Suggested By

Transportation Research Board Special Report 268 Surface Transportation Environmental Research (2002)

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