Consideration of wildlife is increasingly becoming part of transportation planning processes as agencies act to reduce the risk of wildlife-vehicle collisions, improve wildlife connectivity, and save lives. From 2017 to 2022, the Nevada Department of Transportation furthered these efforts leading a transportation pooled fund study that included Federal, State, and Provincial agencies across the United States and Canada, and this article focuses on one study completed by the pooled fund study. There are other products from that study and other efforts, including provisions in the 2021 Infrastructure Investment and Jobs Act (also known as the Bipartisan Infrastructure Law or BIL), seeking to reduce wildlife-vehicle collisions and improve habitat connectivity for terrestrial and aquatic species.

This study, “The Strategic Integration of Wildlife Mitigation into Transportation Procedures,” took lessons learned from State departments of transportation (State DOTs) in the United States, provincial ministries of transportation (MoT) in Canada, and their partners to create a voluntary manual titled The Strategic Integration of Wildlife Mitigation into Transportation Procedures: A Manual for Agencies and Partners to help transportation professionals and their partners incorporate wildlife concerns into planning processes. The manual will support participating agencies and their partners in reducing wildlife-vehicle collisions.

The mitigation the manual refers to helps reduce wildlife-vehicle collisions, and increase connectivity for wildlife beneath, above, and across roadways. This mitigation could take the form of wildlife crossing structures; retrofits of existing bridges and culverts; diversions of airborne birds, mammals, and insects above traffic; pathways along waterways and under bridges to allow for terrestrial passage; animal-detection driver warning systems; and other infrastructure-related additions or changes that reduce transportation impacts to wildlife.

The probability of collisions with wildlife is a factor that agencies consider when planning. The manual focuses on how transportation agencies and their partners can reduce the challenges and effects of wildlife-vehicle conflict. This conflict is defined in the manual to include:

• “Consequences of both terrestrial and aquatic animals’ inability to safely move across roads to necessary habitat across the landscapes,
• Crashes with wildlife,
• Crashes caused by driver actions to avoid hitting wildlife,
• Road avoidance by animals that need to get across,
• Habitat fragmentation,
• Genetic isolation of wildlife populations due to roads, and
• Wildlife population extinction or extirpation.”

The manual was based on the professional experience and expertise of the research team, and the research project’s technical advisory panel for the Wildlife Vehicle Collision (WVC) Reduction and Habitat Connectivity Transportation Pooled Fund Project TPF 5(358).

After 5 years of producing research projects on wildlife and transportation, this collaborative research effort ended in 2022. The partner agencies were led by the Nevada DOT and also included the State DOTs in Alaska, Arizona, California, Iowa, Michigan, Minnesota, New Mexico, Oregon, and Washington. Federal Highway Administration, the Ontario MoT, Parks Canada, and Animal Road Crossing (ARC) Solutions were also participants.

The partners guided the development of the manual and additional reports to provide recommendations that worked within the various agency constraints and planning and operating processes. Nevada DOT’s lead on this project stemmed from their commitment to addressing wildlife-oriented transportation solutions, as relayed by the Nevada DOT’s Environmental Services Chief Christopher Young: “For more than a decade, the Nevada Department of Transportation has been a leader in integrating wildlife crossings into its transportation system. The genesis came out of a vehicle, or user safety approach, but is evolving toward an integrated transportation ecology approach. The work provided by this pooled fund study assesses the groundbreaking work of transportation and resource agencies across North America to provide actionable recommendations for implementing and ensuring the success of wildlife-oriented transportation solutions.”

The results of the study’s 2019 online survey of environmental personnel in State DOTs, Canadian MoTs, and U.S. Metropolitan Planning Organizations (MPOs) and Regional Transportation Planning Organizations (RTPOs) strongly influenced the manual. The invited State DOT participants were selected from the American Association of State Highway Officials (AASHTO) list of members from the AASHTO Committee on Environment and Sustainability. The invited MoT participants were selected after reviewing each MoT’s online resources concerning their environmental professionals. MPO participants were selected from an FHWA master list of 404 MPOs. A smaller sample of these MPOs were selected that represented each State and came from areas near protected forests, preserves, and State or national parks. In all, the survey was sent to 237 State DOT and MoT professionals and 230 MPO personnel. The objectives of the surveys were to learn about the activities and opinions concerning agency inclusion of wildlife considerations in transportation planning procedures and processes. The completed surveys represented 57 respondents in 31 State DOTs, 6 Canadian MoTs, 39 respondents in 27 MPOs in 21 States, and 8 anonymous responses.

Three major themes evolved from the survey results:

1. The most important information sources for integrating wildlife needs were wildlife-vehicle crash data and hotspot analyses of these data;
2. The most important parts of the planning process were collaboration with wildlife agencies and inclusion of wildlife mitigation plans into long-range plans; and
3. The top four most common needs for improvement cited in the responses pertained to collaboration with wildlife agencies, dedicated funding, legislative support to consider wildlife movement needs, and instilling environmental stewardship and awareness within agencies.

The remainder of the research effort focused on these survey results and presented how agencies and partners could insert wildlife connectivity concerns and the reduction of wildlife-vehicle collisions into all aspects of transportation procedures. The manual presented dozens of case studies, websites, and links to best management practice manuals to illustrate how Federal, State, provincial, county, and city agencies and MPOs can institutionalize wildlife considerations into transportation planning processes and procedures. 

The Challenges

Wildlife presents challenges for transportation agencies because of the risks involved with wildlife-vehicle collisions; the conflicts or impacts to survival that roads, railways, and vehicles pose to animals; the protection status of certain species; and the historically limited funding for addressing these challenges.

Transportation agencies’ mission statements and long-range plans generally include goals to reduce the number of dangerous crashes. Reducing crashes with wildlife contribute to this safety goal. Five years of crash data with severity codes for each animal crash were obtained from every State DOT, and animal crashes were used rather than wildlife crashes because 12 States do not report if the animal involved in the crash was wild or domestic. The severity codes ranged from property damage only crashes, to three levels of injury crashes, to fatal crashes, and each crash type had an estimated cost to society. The crashes were analyzed and the annual average number of reported animal-vehicle crashes and their cost for every State were calculated. These numbers were combined for the United States to illustrate how the reduction of wildlife-vehicle collisions is a pressing public safety issue.

For the national perspective, the 2018 FHWA publication, Crash Costs for Highway Safety Analysis, was used to determine dollar-value estimates for various types of crashes. The publication estimates that a human life lost in a vehicle crash is valued at $11,295,400 and the value of a property damage only crash as $11,900, with three levels of injury crashes valued between the two. These values were used to calculate the annual average reported animal crash costs for each State, and for the United States overall.

The conflicts that roads and vehicles pose for wildlife are also a concern to transportation agencies. Wildlife moves across the landscape and waterways to access food and seasonal ranges, reproduce, and escape the effects of climate change. Our transportation routes can place populations of animals at risk by interrupting these movements. The 2008 FHWA report titled Wildlife-Vehicle Collision Reduction Study: Best Practices Manual: Report to Congress estimated that 21 Federally listed or endangered wildlife species are threatened by vehicle collisions. In 2018, 11 western States listed their top wildlife migration corridors for mule deer, elk, and pronghorn in accordance with Secretary of the Interior Order 3362, which instructs U.S. Department of Interior agencies and western State wildlife agencies to take steps to protect ungulate migrations. Every State listed vehicle collisions and roads as major threats to these species and their migratory routes, which highlights the need to protect and accommodate wildlife in transportation planning.

According to survey participants, limited funding has been a part of the challenge when it comes to including wildlife concerns and mitigation efforts in transportation projects, and there has also been limited commitment among transportation agencies and MPOs for addressing wildlife challenges. These two issues were listed by the survey participants as the top reasons their agency did not do more to mitigate roads for wildlife movement. Despite these limitations, the research team found there are several ways to address these concerns, from provisions in national transportation legislation that have set aside designated funding for wildlife mitigation efforts to institutionalizing wildlife considerations into transportation planning processes.

The Solutions

Solution 1—Get Wildlife Considerations into the Planning Process Early

Key actions for instilling State or provincial transportation agency, MPO or RTPO, and Tribal consideration of wildlife connectivity, and a reduction of wildlife-vehicle collisions, are for wildlife to be considered in each organization’s long-range planning and programming processes through institutionalized procedures. These processes can result in creating wildlife crossing structures and other wildlife mitigation projects as standalone projects or as part of other transportation projects.

Long-range planning is generally the first step in the transportation planning process. When the reduction of wildlife-vehicle collisions and consideration of wildlife connectivity are part of the goals and objectives of an agency’s long-range plans, wildlife concerns can become part of an agency’s processes. Wildlife concerns can be added with simple statements, such as including the reduction of wildlife-vehicle collisions as part of a mission statement’s safety goal. An acknowledgement of the risks posed by wildlife crashes is an important first step in reducing them. For example, Steve Gent, director of traffic safety from Iowa DOT says, “In Iowa, 14 percent of all reported crashes involve animals; therefore, it is critical that we consider these crashes as part of our transportation planning processes.” If there is an environmental component, such as a “Do No Harm” statement or protecting the environment, then wildlife connectivity and the creation of wildlife crossings structures can be part of those goals. With these common goals, concerns for wildlife can be better incorporated into each potential project.

Incorporating concerns for wildlife includes considering the National Environmental Policy Act, or NEPA, definition of mitigation in governmentwide NEPA implementing regulations, reflecting the “Do No Harm” conservation hierarchy. Key aspects of the definition can be summarized as avoiding, minimizing, and compensating for impacts to resources. With input from partner agencies, project impacts that would seriously harm wildlife populations may be mitigated or entirely avoided. With enough data and planning, standalone wildlife mitigation projects can be included in an agency’s long-range plans to rectify situations where motorists and wildlife are at risk of collisions and where wildlife need assistance in connectivity across transportation corridors. Finally, all potential projects in the long-range plans that occur in areas with wildlife should consider and mitigate for impacts to wildlife.

Programming is usually the next step in the transportation process. Here, too, wildlife concerns should be identified and incorporated into transportation plans, which in the United States, results in a State Transportation Improvement Program (STIP). STIPs are multiyear planning documents that list potential projects in an agency’s long-range plan in detail and, with funding sources identified. Each transportation agency has its programming process for prioritizing what projects are moved to the STIP. The information sources used to prioritize projects in programming include planning studies, MPOs’ and RTPOs’ transportation plan priorities, stakeholder priorities, and priorities of the transportation agency’s divisions at headquarters and the districts. The plans and information, external relationships, and different levels of professionals in a transportation agency offer a rich variety of approaches to include wildlife and wildlife-vehicle collision safety concerns in upcoming STIP projects, or create standalone wildlife transportation mitigation projects. The inputs to the programming step that help identify the importance of wildlife connectivity and the reduction of wildlife-vehicle collisions include:

• Data and hotspot analysis on wildlife-vehicle collisions.
• Agency maps of wildlife habitats and where wildlife need to move across roads.
• Locations of upcoming transportation projects in the long-range plan and the STIP, and where those areas intersect the wildlife-vehicle collision hotpots and wildlife movement maps.
• Expertise of personnel within agencies whose role is specified to put forward projects that help reduce wildlife-vehicle collisions and find ways to provide connectivity for wildlife populations.

The Nevada DOT prioritized areas of wildlife-vehicle conflict across the State with a study that identified both the animal crash hotspots and the wildlife habitats that are bisected by roads. The results have been used to recognize areas with wildlife conflicts for ongoing consideration and planning of potential wildlife crossing structures and other mitigation measures to reduce wildlife-vehicle collisions and restore wildlife connectivity.

New Jersey’s Division of Fish and Wildlife maintains an interactive website that helps identify key areas where actions are needed for wildlife connectivity through its Connectivity Habitat Across New Jersey program. The interactive map helps to guide mitigation of road barriers to wildlife movement and can be used in early long-range planning.

Solution 2—Partnerships

Transportation agencies’ stakeholders can help institutionalize wildlife concerns throughout the transportation planning process. The most successful efforts to date to include wildlife crossing structures in transportation projects, and overall, in a transportation agency’s planning, come from working with other Federal and State agencies, nonprofit organizations, Tribes, and members of the public interested in establishing mitigation measures to reduce wildlife-vehicle collisions. These efforts include working with MPOs and RTPOs in the development of their transportation plans, which are included in the STIP; working with Federal agencies and Tribes to identify the most important areas to apply mitigate measures for wildlife and to secure Federal funding; and working with the State or provincial wildlife agency to identify key areas for wild animal movement while securing funding and public support for wildlife mitigation projects.

MPOs and RTPOs can be important contributors to providing wildlife connectivity mitigation. MPOs cover urbanized areas with a population of more than 50,000 while RTPOs cover geographic areas with a population of less than 50,000. MPOs and RTPOs carry out metropolitan and regional transportation planning processes respectively, which are incorporated in the development of long-range statewide transportation plans and STIPs. However, State DOTs administer only 18.8 percent of the roads across the United States. The remaining roads are under the jurisdiction of MPOs and RTPOs, Federal agencies, counties, and others. Thus, it is important these organizations identify wildlife connectivity and wildlife-vehicle conflict problem areas as important factors in their transportation plans and help find funding sources to support wildlife mitigation actions, creating win-win solutions.

In Tucson, AZ, Pima County residents voted to impose a local tax that would fund wildlife connectivity projects. As of 2022, the tax raised $45 million for wildlife crossings and land protection projects into 2026. Pima County authorized the Regional Transportation Authority to build several wildlife crossings with Arizona DOT and more are planned in southern Arizona.

From the development of long-range transportation planning to everyday transportation operations and maintenance, wildlife agencies are important partners for transportation agencies. Federal and State wildlife professionals can identify locations of protected and other important wildlife species. This work in turn helps transportation agencies avoid and minimize transportation impacts to wildlife using crossing structures and other types of mitigation measures that reduce crashes and provide safe connectivity. Some wildlife biologists can also suggest the optimal crossing structures for target species; however, transportation ecologists, who are often outside these agencies, may know best the science and practice of transportation ecology and the proven effective designs for specific species. Wildlife agencies and nonprofit organizations can also provide funding for projects.

The most robust programs in States and provinces with dozens to hundreds of wildlife crossing structures have a memorandum of understanding, or MOU, between the wildlife and transportation agencies, regular meetings, and some regulatory power for the State, provincial, or Federal wildlife agency to approve transportation projects. There are also active research programs in States and provinces that create wildlife crossing structures and other mitigation measures, which evaluate how well the mitigation infrastructure meets performance measures, and assists in developing future effective mitigation.

In 2017, Colorado’s DOT and Colorado Parks and Wildlife, in coordination with FHWA, sponsored a two-day Wildlife and Transportation Summit that resulted in the formation of the Wildlife and Transportation Alliance. The working relationships among these agencies and many other members of the Alliance have resulted in prioritization of top wildlife connectivity areas across the State. Some wildlife mitigation measures and additions to upcoming projects to help wildlife move under roads have been developed at these locations. Additionally, Governor Polis’ 2019 executive order, “Conserving Colorado’s Big Game Winter Range and Migration Corridors,” reinforced the Alliance’s ongoing work.

Legislation promoted by nonprofit conservation organizations at the State and national level have resulted in both providing additional funds for wildlife mitigation efforts, and in persuading transportation agencies to identify and prioritize areas of wildlife connectivity or corridors across transportation infrastructure. The most significant legislation in the U.S. is the BIL, which has 10 funding sources that can be used to create wildlife crossing structures. These funding sources include the Wildlife Crossings Pilot Program (23 U.S.C. 171), which is a 5-year, $350 million program for reducing the number of wildlife-vehicle collisions and, in carrying out that goal, improving habitat connectivity for terrestrial and aquatic species. This program will fund wildlife-transportation mitigation projects through a competitive process providing grants to eligible entities including Federal land management agencies, States, Tribes, and local land management and transportation agencies.

States are also passing legislation to incentivize collaboration between transportation and wildlife agencies to identify places where wildlife need to move across roads, and to institutionalize efforts to work together on behalf of wildlife. In 2019, the New Mexico governor signed the New Mexico Wildlife Corridors Act. The New Mexico DOT then supported a study where wildlife movement requirements and areas of wildlife-vehicle collision hotspots were combined with other information to create the New Mexico Wildlife Corridors Action Plan. The plan provides a list of the top 11 priority locations for wildlife mitigation measures and recommends locations and types of structures to be placed to provide wildlife connectivity.

Solution 3—Agency Culture Change

Transportation agencies can also make changes from within to help create a culture of awareness for wildlife concerns while institutionalizing actions to ensure wildlife will be included in planning and other parts of their transportation processes.

Transportation agencies can include wildlife consideration in their professional manuals to institutionalize wildlife concerns. Texas DOT (TxDOT) commissioned a study, “Incorporation of Wildlife Crossings into TxDOT’s Projects and Operations,” to assess how recommendations to consider wildlife can be written into TxDOT professional manuals. This resulted in specific instructions for 18 professional manuals, including manuals for planners, traffic safety engineers, and maintenance professionals.

Transportation agencies can also create a formal education program for all professions to better understand the need for wildlife connectivity and the prevention or reduction of wildlife-vehicle collisions. The Vermont Transportation Agency offers the Vermont Highways and Habitat Program, where agency participants go into the field to see how wildlife move near roads, track and photograph wildlife, handle snakes, other reptiles, and amphibians, and work with wildlife professionals to better understand how the transportation agency’s actions affect wildlife of all kinds. These working field trips help planners, engineers, and maintenance personnel discover how the agency’s roads intersect with wildlife movement paths and what they can do to help the wildlife. This training program won a 2022 FHWA Environmental Excellence Award.

A transportation agency can have an official wildlife program where a point person and team are the go-to professionals to help with all things wildlife. In British Columbia’s Ministry of Transportation and Infrastructure, the wildlife program leader briefs all new hires individually on wildlife concerns in transportation. This individual also creates a robust social media presence to inform employees and the public about wildlife and road compensation projects. 

Next Steps and Recommendations

“The Strategic Integration of Wildlife Mitigation into Transportation Procedures” study found that transportation agencies can make great gains by installing wildlife crossing structures in larger transportation projects. However, these efforts are often inadequate because wildlife mitigation practices are not typically institutionalized within their organizations. Some of the opportunities for transportation agencies to include wildlife considerations in everyday actions are based on incremental changes that do not garner headlines and attract social media stories.

The manual The Strategic Integration of Wildlife Mitigation into Transportation Procedures: A Manual for Agencies and Partners recommends three major changes for agencies to consider:

1. Wildlife need to be considered in a transportation agency’s standardized procedures.
2. Transportation agencies and MPOs should work with outside agencies and others to plan, fund, and construct wildlife crossing structures.
3. Transportation professionals need to be inspired to consider wildlife in their everyday actions.

These three changes create a culture of care for wildlife that results in actions to mitigate barriers to wildlife movement and makes roads safer for the motoring public.

For more information, see The Strategic Integration of Wildlife Mitigation into Transportation Procedures: A Manual for Agencies and Partners (https://pooledfund.org/Details/Study/610) for how agencies and partners can standardize wildlife considerations in transportation procedures, from planning and project construction to everyday maintenance and operations and include wildlife in their processes. Scroll to the Documents pull down menu, and look for publications with Cramer as the author. Note: There are other parts of the Transportation Pooled Fund Study research effort that have reports on this site as well.

Daniel Buford is an ecologist with FHWA’s Office of Planning, Environment, and Realty (HEP). He was the FHWA Technical Liaison for the Wildlife Vehicle Collision Reduction and Habitat Connectivity Pooled Fund Study.

Patricia Cramer is an independent wildlife researcher specializing in wildlife crossing structures, and planning for wildlife in transportation. She specializes in western States. Dr. Cramer was the principal investigator for this study.

Nova Simpson is Nevada Department of Transportation’s Northern Nevada biological supervisor and large mammal mitigation specialist. She was the study champion and project manager for the pooled fund study.

For more information on the integration of wildlife connectivity into the transportation planning process, visit https://www.wildlifeconnectivity.org/national-study-to-integrate-wildlife-into-transportation, or email Dr. Patricia Cramer (cramerwildlife@gmail.com), Nova Simpson (NSimpson@dot.nv.gov), or Daniel Buford (daniel.buford@dot.gov).