An exploration of the high cost of wildlife-vehicle collisions and the
many challenges to transforming the U.S. road network.
Documentation of the safety, ecological, economic, and social benefits
anticipated to accrue from investing in highway crossings for wildlife,
including enhanced motorist safety, reduced wildlife mortality, and improved
Identification of policy and funding improvements and activities that
would further support the deployment of crossing structures.
Recommendations on how to build upon successful efforts to reduce
wildlife-vehicle collisions already underway at the federal, state, local, and
WTI Road Ecology Program Rob Ament served as one of the editors for the report, and WTI Research Scientists Tony Clevenger, Marcel Huijser, and Angela Kociolek are contributing authors.
CITATION: Ament, R.; Jacobson, S;
Callahan, R.; Brocki, M., eds. 2021. Highway crossing structures for wildlife:
opportunities for improving driver and animal safety. Gen. Tech. Rep.
PSW-GTR-271. Albany, CA: U.S. Department of Agriculture, Forest Service,
Pacific Southwest Research Station. 51 p.
The New York Times has posted an online feature article highlighting excellent footage of wildlife using various forms of highway crossings. “How Do Animals Safely Cross a Highway? Take a Look” includes footage of a herd of antelope crossing a highway in Wyoming; moose, bear, wolves and deer using crossings in Utah; and an alligator and panther using underground passages in Florida. WTI Road Ecologist Marcel Huijser was interviewed for the article in which he discusses that despite the upfront installation costs, wildlife crossings yield significant safety and conservation benefits that save money in the long run. Whisper Camel-Means, a tribal wildlife program manager who collaborated with WTI on US 93 wildlife crossing projects in Montana, was also interviewed for the article.
WTI recently completed a feasibility study for a “Smart” transit hub to serve an eight-county rural region in western Arkansas and eastern Oklahoma. The study presents a menu of technologies and programs that help connect people experiencing transportation barriers in rural communities to healthcare, employment, and higher education opportunities.
WTI’s Small Urban, Rural and Tribal Center on Mobility (SURTCOM) conducted the project in partnership with the National Association of Development Organizations (NADO) Research Foundation, Western Arkansas Planning and Development District, and Frontier Metropolitan Planning Organization (MPO). NADO and WTI have been collaborating on a series of projects that assist rural communities with passenger transportation projects that enhance mobility options for residents.
“A traditional transit hub is a physical location where travelers can access multiple services in one place,” said Principal Investigator Rebecca Gleason; “while physical hubs are not always viable in rural areas, regional coordination and emerging technologies offer new ways to connect people to transportation information and services.” The study findings, which are highlighted in a newly released Executive Summary, include recommendations that can be implemented over time, such as hiring a regional mobility manager, exploring methods to connect more people with rides on existing systems, creating a 5-year transit development plan, and piloting a new transportation program. The Executive Summary and full study are available on the project page of the WTI website.
Roads can be dangerous for California’s reptiles and amphibians, but a five-year study and new video show that there are effective strategies to help these animals cross roads safely.
The California Department of Transportation (Caltrans) released the results of the study this week in a comprehensive, evidence-based best practices guide that explains approaches and techniques for minimizing the impact of roads on fragile and diminishing habitats and species, including frogs, toads, salamanders, turtles, lizards and snakes.
practices guide is the first of its kind for amphibian and reptile management
and conservation near California roads.
“It is no
longer a case of putting a few pipes and fences into the ground with a ‘fit and
forget’ approach,” said Tom Langton of Herpetofauna Consultants International,
Ltd., primary author on the guidance document. “This guide offers resource
managers in California opportunities and a clear plan to improve existing
crossings and build new ones to better standards where they are most needed. The guidance should be valued in
other states with similar wildlife-road issues and at the international level,
and amphibian species must cross roads to reach essential breeding and foraging
habitat, are slow moving or
are too small for drivers to see and avoid. Snakes and lizards may also be attracted to paved roads
that typically absorb and retain heat.
All these behaviors put them at high risk of vehicle collisions.
have a responsibility to maintain the highway system in a way that doesn’t
impede or disrupt wildlife, including the movement of California’s threatened
and endangered reptile and amphibian species,” said Caltrans Director Toks
Omishakin. “This study allows us to analyze feasible and
effective ways Caltrans can use ecologically-minded design to minimize
impacts on these wildlife populations.”
transportation agencies and wildlife managers have installed structures to
help amphibians, reptiles and other small animals cross highways safely, such
as tunnels under roads or barrier fencing.
agencies have made significant investments in these structures for many years,
there has been little research into how effective they are,” said Dr. Robert
Fisher, a U.S. Geological Survey (USGS) supervisory ecologist involved in the
study. “Management guidance informed by science is needed to help ensure this
critical infrastructure is safe for sensitive species.”
With these concerns in mind, the goals of the
collaborative project were to address this information gap using a logical
framework and to help transportation agencies like Caltrans plan barrier and
crossing structures more effectively.
To help Caltrans determine which reptile and amphibian
species to prioritize, USGS scientists created a ranking system for more than
160 species and sub-species, based on their vulnerability to road dangers.
Turtles, tortoises and snakes dominated the highest risk category. USGS also
developed a mapping system to allow Caltrans to easily find where the ranges of
high-risk species overlap with California highways and statewide conservation
efforts. Species ranked high and very-high risk of negative road-related
impacts include desert tortoise, California red-legged frog, sierra newt and
red diamond rattlesnake, among others.
Then, in a series of field experiments, the USGS
scientists investigated how reptiles and amphibians interact with different
types of fencing, how far high-risk migrating amphibians move along road
barrier fencing before “giving up” or finding a passage, and the effectiveness
of turnarounds at fence ends.
“We were happy to find that turnarounds at barrier fence ends were largely effective in changing the trajectory of many species to help lead them back toward a passage,” said Cheryl Brehme, the USGS project lead. A new video by USGS shows a California tiger salamander successfully make it to an underground crossing after being guided by one of these turnarounds.
“The elevated road-segment is really exciting,” said
Brehme, “because it can be made to any width and length enabling reptiles,
amphibians and other small wildlife species to freely move back and forth
across wide stretches of roadway.”
Caltrans used the results of these combined studies to produce the best management practices guide, which will inform the work of district biologists and engineers and will likely be useful to many other organizations involved in the planning and construction of transportation infrastructure. USGS has also released a comprehensive reportof its studies in conjunction with the new guidance document.
emphasizes that different landscapes – and different species – need a range of
solutions, and the needs of different species and their numbers will influence
positioning and sizes.
“Planning for smaller rare species calls for designs that take into account the sensitivities and needs of these understudied and often forgotten species” said Dr. Tony Clevenger of Western Transportation Institute, who led the development of the best management practices guide. The best practices guide was produced for Caltrans by the Western Transportation Institute of Montana State University with Herpetofauna Consultants International, Ltd and is based on existing knowledge and foundational studies by the U.S. Geological Survey Western Ecological Research Center.
California Department of Transportation (Caltrans)
Amy Bailey, Supervising Environmental Planner
The Clear Roads research program, which sponsors practitioner-focused winter maintenance research, is highlighting a recently completed severity index project on its website. For “Evaluation of SSI and WSI Variables,” the Narwhal Group and WTI collaborated to create a step-by-step guide to support implementing a severity index, paired with a flowchart tool that helps match users with existing indexes.
These tools will help winter maintenance agencies select the most appropriate storm severity index and winter severity index to compare storms across more than one winter season. “While a number of severity indexes exist, determining if you can apply or modify one for your needs or develop your own can be a daunting task. This guide and flowchart tool will support agencies in this task,” said Cold Climates Program Manager Laura Fay, who served as a co-PI. The final report is available on the WTI project webpage and there is a research brief on the Clear Roads project page.
Public Policy magazine In These Times recently interviewed WTI Road Ecologist Marcel Huijser for an in-depth article on wildlife crossings. “Toward a World Without Roadkill” highlights efforts by residents and local organizations near Great Smoky Mountains National Park to reduce the rising number of bears, deer, and elk being hit by vehicles on Interstate 40. Marcel discusses how mitigation efforts such as wildlife crossings can have significant conservation, safety, and economic benefits.
Along a historic parkway in Virginia, the National Park Service (NPS) will soon begin improvements to enhance safety for drivers, pedestrians, and cyclists. In a recent news release, the NPS announced planned safety measures for the George Washington Memorial Parkway, which runs along the Potomac River near George Washington’s Mount Vernon Estate. The Parkway serves recreational and tourism users, as well as a growing number of commuters, which has led to increased congestion and safety challenges.
The recommended improvements stem from a major safety assessment conducted by WTI and Mead & Hunt on behalf of the Eastern Federal Lands Highway Division (EFLHD) of USDOT. The GWMP Traffic and Safety Context Sensitive Solutions Assessment, led by Principal Investigator Natalie Villwock-Witte, studied traffic conditions and crashes at nine intersections on the Parkway, then developed individual recommendations for each. Proposed alternatives were designed to enhance safety, while maintaining the character of a national park setting. The full report is available on the project webpage.
Two WTI Road Ecology
Researchers will be the main presenters at a webinar on Tuesday, April 13,
at 11 am Mountain Time.
The National Center for Rural Road Safety (Rural Safety Center) is hosting a FREE, 1.5-hour online webinar on “Road Observation and Data System Project: Streamlining Animal-Vehicle Collision Data Collection.” This webinar will feature an overview of a wildlife-vehicle collision (WVC) data collection system called ROaDS (Roadkill Observation and Data System), a user-friendly tool to collect information on vehicular crashes with large-bodied wildlife for both motorist safety and conservation purposes.
WTI Road Ecologists Rob Ament and Matthew Bell will be the presenters for this webinar, which will be of interest to transportation practitioners, Federal land management agency (FLMA) transportation managers and planners, and wildlife conservation personnel. For more information, visit the event registration page.
The impact of extreme weather on transportation systems and infrastructure was the focus of a recent feature article by the National Academy of Sciences’ Transportation Research Board. In “Preparing for Winter Weather with Transportation Resources,” TRB interviewed WTI Research Scientist and Cold Climates Program Manager Laura Fay about the importance of prevention in the winterization process. Fay, who serves on TRB’s Standing Committee on Winter Maintenance, discussed how good prevention for maintaining roads starts with road design and continues with the decisions made before, during, and after a storm hits.