WTI

Guidelines for Designing and Evaluating North American Wildlife Crossing Systems

Primary Investigator Contact Information

External Project Contact(s)

Report(s)

1. Crossing to Safety: Executive Summary of the FHWA Handbook for Design and Evaluation of Wildlife Crossing Structures in North America
   1. Anthony P. Clevenger and Marcel P. Huijser
   2. 425259_Executive_Summary.pdf
2. Handbook for Design and Evaluation of Wildlife Crossing Structures in North America
   1. Tony Clevenger and Marcel Huijser
   2. 425259_Final_Report.pdf

Project Objective

To provide transportation professionals with the best available information and current technologies on wildlife crossing systems for transportation projects.

Project Abstract

Effective wildlife fencing and crossing structures can significantly reduce many harmful impacts of roads on wildlife populations. Yet currently there is limited knowledge of how to incorporate these structures for most wildlife species into transportation projects. For example, studies have shown that wildlife use crossing structures, but level of use varies between species of wildlife, locations and landscapes, and the reasons why are unclear. Recommended minimum dimensions have been suggested for some ungulate species, but the needs of wide-ranging species are vague at best. Human activity can significantly influence how wildlife use structures. Others have inferred that crossing structure location, particularly in relation to habitat quality, might be the most important design feature of successful wildlife crossing structure applications. In spite of these valuable kernels of information, gaping holes in our knowledge of functional wildlife passage systems remain. Practically all of the performance evaluations to date have focused on single-species and limited attention has been paid to multiple-species relationships. After nearly a decade of increased activity building crossing structures, engineers and land managers still lack guiding principles as a large void exists in devising functional designs based on criteria that are relevant to real management decisions. It is timely to conduct a critical assessment of the current status of these mitigation measures and experience in an adaptive management process. A growing body of literature and information base has resulted from nearly a decade or more of increased implementation of wildlife crossing systems in North America. This project serves as the first attempt to gather, review and critically analyze current information on ecological criteria and design attributes of wildlife crossing structure planning and performance. We will obtain data on specific passage use from reports in journals, conference proceedings, in-house technical reports and informal contacts with colleagues.

Task Descriptions

1. Literature Review
   1. Review and synthesize current knowledge of North American wildlife crossing systems as it pertains to their design, monitoring and performance criteria.
2. Address Other Issues
   1. Elaborate on specific crossing structure design issues, e.g. openness ratios, siting, spacing intervals, and management of land use and human disturbance. Discussion of these specific issues will help transportation practitioners better understand the complexities of these questions, the importance of context in decision-making, and the informational constraints facing them today. Identify priority areas for continued research.
3. Develop Guidelines
   1. Develop guidelines (based on baseline information gathered during the literature review) for planning and designing functional wildlife crossing structures as they relate to key regional wildlife communities, fragmentation-sensitive species, and transportation management concerns (e.g. National Environmental Policy Act [NEPA], Endangered Species Act [ESA], wetlands, public safety, etc). Our report will provide examples from representative case studies that measured wildlife crossing structure performance using a variety of study methods pre- and/or post-construction.
4. Draft Progress and Final Reports
   1. Provide quarterly progress reports summarizing project activities and current project costs; semi-annual reports summarizing results of the project and changes in direction or schedule; and a comprehensive final report, not later than 18 months from initiation of the project.
5. Develop Protocols
   1. Develop protocols for monitoring wildlife crossing structures programs.

Milestones, Dates, Schedule

Student Involvement

True

Relationship to Other Research Projects

False

Technology Transfer Activities

True

Transportation Research Board Keywords

Case Studies, Traffic Safety, Wildlife

Partners