Wildlife Crossing Structures

Focus Area

Wildlife & Ecosystems


Natural Resources






Over 3 years

Research Idea Scope

Monitor different crossing structures to determine which kinds work best.

TERI Administrator Note (June 2007): Research Completed (See Below)

NCHRP – Evaluation of the Use and Effectiveness of Wildlife Crossings, NCHRP Report 25-27 (2007)

Every year, the costs of personal injuries and property damage resulting from animal/vehicle collisions are considerable. Various means have been employed to mitigate these collisions, with varying degrees of success. In recent years, highway agencies have placed a growing emphasis on protecting the environment. While many smaller species of animals do not pose a threat to vehicles through collisions, they experience significant habitat loss and fragmentation as a result of roadway alignments. Transportation corridors limit the natural movement of wildlife, affecting individual species and ecosystems. There has been considerable research on the provision of wildlife crossings, but there is a lack of data on their effectiveness and on the methods most effective for a particular species in a particular landscape. It also appears that crossings may work well for one species but not for others. A recent international scan on wildlife habitat connectivity documented various strategies and designs used in Europe to improve the connectivity of wildlife habitats. Developing successful designs, methods, and strategies to make roadways more permeable to wildlife is but one aspect of managing highways to avoid or minimize affects to the natural environment and maintaining safety for motorists. There is a need to provide state DOTs with guidance on the use and effectiveness of wildlife crossings to mitigate habitat fragmentation and reduce the number of animal/vehicle collisions on our roadways. The objective of this project is to develop guidelines for the selection (type), configuration, location, monitoring, evaluation, and maintenance of wildlife crossings.

Montana DOT – Wildlife-Highway Crossing Mitigation Measures & Associated Costs/Benefits: A Toolbox for Montana Department of Transportation (2007)

The objective of this project is to aid the Montana Department of Transportation (MDT) with the decision-making process regarding the choice of mitigation structures that reduce animal-vehicle collisions, and provide habitat connectivity for wildlife, for current and future projects. Reducing animal-vehicle collisions and improving habitat connectivity for wildlife across roadways are important factors to consider in highway construction or improvement projects for human safety, economic and ecologic reasons. The estimated 725,000 to 1,500,000 collisions between motor vehicles and wildlife result in more than 200 human fatalities, 29,000 human injuries and over 1 billion dollars in property damage in the United States alone each year. In addition, highways can be a movement barrier to many species, causing habitat fragmentation and, sometimes, reduced survival probability for the population concerned. Engineers and biologists have tested a variety of potential solutions to the safety, economic and ecologic conflicts between wildlife and highways. Many years of work have resulted in substantial knowledge about the application and effectiveness of a wide array of mitigation measures deployed worldwide. However, knowing which mitigation measures address a particular problem, and which would be suitable given local circumstances can be challenging. MDT has contracted with the Western Transportation Institute (WTI) to provide an overview of mitigation measures that reduce animal-vehicle collisions and allow animals to cross the road safely.

FHWA Report FHWA-PL-02-011Wildlife Habitat Connectivity Across European Highways 2002

Habitat and wildlife resources around the world have diminished to the point that transportation agencies are being asked to address impacts to these resources when implementing improvements to transportation systems. The Federal Highway Administration (FHWA), American Association of State Highway and Transportation Officials (AASHTO), and the National Cooperative Highway Research Program (NCHRP) sponsored an international technology scan to learn what actions are being taken in Europe to address habitat and wildlife issues. A delegation of federal, State, and conservation group representatives visited Slovenia, Switzerland,
Germany, France, and the Netherlands to observe and document efforts in Europe.

As a result of the trip, the team formed conclusions and recommendations for U.S. applications in the areas of policy, communications, guidance manuals, and research. In particular, the group recommends (1) including wildlife/transportation issues in the FHWA and AASHTO strategic plans; (2) creating a central source of contact for international exchange of information; (3) developing a number of guidance manuals pertaining to assessment methodologies, interagency coordination, terminology, and structures design; and (4) using pooled funds to study connectivity needs for all types of wildlife; and (5) funding a national connectivity study.

Urgency and Payoff

Reduction of wildlife collisions with vehicles, and better wildlife connectivity.

Suggested By

Paul West, Utah Dept of Tranportation

[email protected]