Wyoming DOT Completes Dry Piney Wildlife Crossing

The Wyoming Department of Transportation recently completed a long-awaited project aimed at reducing wildlife-vehicle collisions along the Green River in western Wyoming.

[Above image by Wyoming DOT]

The agency released a video detailing how wildlife crossings built as part of its $15.1 million Dry Piney project will help reduce wildlife-vehicle collisions.

The Dry Piney project – a joint effort between the Wyoming Game and Fish Department and the Wyoming DOT – includes nine underpasses and 16.7 miles of eight foot-high fencing on both sides of Highway 189 in the western part of the state to protect big game animals, primarily mule deer.

Construction of wildlife crossing infrastructure is getting a national boost via a new pilot project launched by the U.S. Department of Transportation in April; an effort funded by the $1.2 trillion Infrastructure Investment and Jobs Act or IIJA.

That pilot program – dubbed the “Wildlife Crossings Pilot Program” and managed by the Federal Highway Administration – will make grant funding available to states and communities to construct wildlife crossings over or below busy roads, add warning signs for drivers, acquire mapping and tracking tools, and more.

Above Image by FHWA

FHWA is making a total of $350 million available over five years, including more than $111 million in grants through its first round of funding in 2023. The agency also noted that roughly 200 people are killed – and many more are injured – annually in the United States in more than one million collisions involving wildlife and vehicles.

recent blog post by the Pew Trusts highlights how the growing success of wildlife crossings – bridges, underpasses, and culverts designed to help animals avoid vehicle traffic – across the U.S. is drawing a surge of interest from policymakers seeking to reduce wildlife-vehicle collisions and protect animals.

Meanwhile, state departments of transportation have already been working on a variety of wildlife-vehicle collision prevention initiatives over the last several years.

For example, to date, Colorado DOT said it has built more than 60 wildlife mitigation structures crossing above or under highways throughout the state. Additionally, it has installed 400 miles of high big game fencing along state and U.S. highways or next to the interstates.

In August 2022, the agency completed a wildlife overpass and underpass on U.S. Highway 160 in the southwestern part of the state; a stretch of road where more than 60 percent of all crashes are due to wildlife-vehicle collisions.

Concurrently, a research document released in July 2022 by an international pool funded study led by the Nevada Department of Transportation provides an “authoritative review” of the most effective measures to reduce animal-vehicle collisions, improve motorist safety, and build safer wildlife crossings.

WSDOT Builds Sustainability into Multimodal Hub Project

In a recent blog post, the Washington State Department of Transportation detailed how it is building sustainability into the I-405/NE 85th St Interchange and Inline Bus Rapid Transit or BRT Station project – an infrastructure endeavor that marks the start of work on the Stride BRT public transit system on I-405.

[Above photo by WSDOT]

Constructed in concert with Sound Transit, the City of Kirkland, design-builder Graham Contracting Ltd., and many regional partners, this new “multimodal hub” includes wider sidewalks on Northeast 85th Street and improved BRT connectivity to the broader regional transit network.

At the same time, the project is building convenient direct access ramps to the I-405 express toll lane or ETL system to help streamline highway commuting for carpooler and ETL users.

Yet WSDOT stressed that the new NE 85th Street Interchange “multimodal hub” does not just make carpooling and using public transportation more convenient; it also incorporates several key environmental stewardship aspects as well:

  • Removing fish barriers: WSDOT plans to remove and correct a fish barrier as part of this project; helping sustain and grow salmon and steelhead fish populations while meeting tribal treaty obligations. Fixing fish barriers is essential for preserving ecological balance, sustaining local economies, respecting cultural traditions of local tribes, and creating jobs, while promoting the long-term health and resilience for the state, WSDOT said.
  • Replanting native, adaptive plants, and trees: While some tree removal is necessary during construction, WSDOT aims to minimize it as much of that as possible. Many trees removed from the project site will be “repurposed” for stream habitat restoration. Then, at the end of construction, WSDOT plans to replant more trees than were removed; focusing on native species to improve the environment and control non-native plants.

During a construction kick-off event for this multimodal hub, Penny Sweet – mayor of the City of Kirkland – noted that the neighborhood surrounding the project site should be able to “blossom” with opportunities for affordable housing and park amenities, as well as new commercial and retail services.

“Kirkland is all in on BRT and the amazing interchange that will make it all possible,” she said. “We will continue to be an ally and advocate in bringing this generational mobility infrastructure to life.”

Iowa DOT Details Wetlands Preservation Efforts

The Iowa Department of Transportation recently detailed in a blog post the “balancing act” required in order to minimize the impact of road and bridge construction projects on the environment.

[Above photo by the Iowa DOT]

That “balancing act” can also result in environmental revitalization as well, the agency stressed, such as for wetland areas that improves wildlife viewing, hunting, and other outdoor activities.

“By law, we are required to avoid and minimize impacts to water resources if we can. If that’s not possible, we will work to mitigate any impacts, often going above and beyond what is required if there is a cost-effective way to get that done,” explained Brandon Walls, a project manager in the water resources section of the Iowa DOT’s Location and Environment Bureau.

“In a nutshell, it means we can’t avoid impacts to water resources in the construction area, so we make up for the damage to the wetlands or streams in the construction area somewhere else,” he said.

Walls pointed to an Iowa DOT-constructed wetland mitigation site near Steamboat Rock in Hardin County as an example of the agency’s mitigation efforts. That site, called Hoover Ruby Wildlife Area, is owned by the Hardin County Conservation Board and was constructed to offset wetland impacts associated with two U.S. 69 Bridge replacement projects in Wright and Hancock counties.

“Because the impacted areas contained both emergent and forested wetlands, we [Iowa DOT] were responsible for re-creating those types of wetlands in this area owned by Hardin County,” he noted.

“We also work with the Army Corps of Engineers on mitigation sites to ensure we are developing enough wetland areas of a certain quality to meet the permit requirements,” Walls pointed out. “This specific permit required us to build 1.76 acres of emergent wetland and 0.4 acres of forested wetland, but we thought it was necessary to go beyond those baseline requirements to provide an area that would be more useful.”

He said that a successful forested wetland can be particularly challenging to reconstruct. Although the emergent wetland at Steamboat Rock is thriving, the trees originally planted in the forested wetland portion didn’t survive after they were planted, so Walls and his team engaged in a second round of seedling planting.

[Editor’s note: The Wyoming Department of Transportation is engaged in a similar wetlands restoration effort as part of its Snake River channel project.]

“We’re trying to keep as much of this work in-house to replant the forested wetland so we can to keep the costs down,” he explained. “We worked with the State Forest Nursery to get seedlings, which cost less than $300. I asked for volunteers from our bureau to help me plant the seedlings. Nine of us planted 225 trees of four species that like to have their feet wet.”

In another cost-saving measure, Walls and the team recycled tree tubes used to support the young saplings and protect them from being eaten by deer. “The saplings are very small and hard to see,” he added. “We went out and collected protective tubes from another wetland mitigation site that had grown up enough to not need them anymore.”

Walls will be responsible for monitoring this site for the next few years to make sure it succeeds and grows into a successful wetland area. “I have trail cameras out there and one of the coolest things I’ve seen is a pair of Sand Hill Cranes,” he said. “They haven’t been spotted much in Hardin County, so seeing them use our site is exciting.”

Once the entire wetland is functioning as it should, the Hardin County Conservation Board will take over the monitoring and maintenance long-term. “This is going to be a really nice resource for the public to hunt and view wildlife,” Walls noted.

WSDOT Crews ‘Go Fishing’ in Stream Realignment

Construction crews with the Washington State Department of Transportation are often called upon to execute unusual tasks within their road building and maintenance activities – and that can include “going fishing” as part of stream realignment efforts.

[Above photo by WSDOT]

The agency noted in a recent blog post that a good portion of its transportation infrastructure work involves streams and wetlands, especially in the Pacific Northwest, where roads, streams, and wetlands often intersect.

For example, WSDOT pointed to the SR 167 Completion Project in Pierce County – located in an area where I-5 crosses over Hylebos Creek at the Fife curve, with tributaries and wetlands on either side of the freeway. As a result, WSDOT construction crews made changes so the freeway, creek, and wetlands can co-exist in harmony – work that included a wetland and stream restoration project, revitalizing almost 150 acres of land on either side of I-5 near the Fife curve.

[Editor’s note: The Federal Highway Administration recently issued $196 million to 59 tribal, state, and local governments to help fix or remove 169 culvert barriers to improve fish passage. The agency said outdated culverts and other related infrastructure can cause roads to flood and severely restrict or altogether block fish passage.]

As part of that restoration effort, in mid-July, WSDOT crews removed fish from Hylebos Creek so they could rebuild and realign a 2,200-foot section of the stream by mid-September. Crews carefully removed fish from the stream’s work zone and relocated them another area of the creek where they won’t be affected by construction work – a process technically known as “de-fishing,” the agency explained.

WSDOT noted its crews are only allowed to step foot or put equipment into a stream during a designated “fish window,” which is often mid-summer to early fall, depending on the stream, when the fewest number of fish are generally present.

The agency stressed that its crews are not “fishing” in the traditional sense when conducting such “de-fishing” operations. They set up and secure fine-meshed netting, dragging it in the water to encourage fish to naturally swim downstream away from the construction area – basically “shooing” them out of the area – as it is less stressful for the fish if they can swim away on their own. The crews will then secure another fine-meshed net in the stream to block off the area they just waded through so the fish do not return to the just-cleared area.

WSDOT noted that any fish stragglers trapped between the two secured nets are removed first by “seining passes” followed by “electro-fishing,” whereby a very small electrical charge in the water temporarily stuns the remaining fish so they can be gently scooped up in nets by trained fish handlers. WSDOT noted that crews keep moving downstream, repeating this entire process, until all the fish are caught and relocated safely from the construction area.

Georgia DOT’s Prescribed Burns Help Pitcher Plant

A recent video posted by the Georgia Department of Transportation details how the agency is helping “rejuvenate” a rare species of vegetation commonly known as the “​Pitcher Plant” along State Route 177 on the way to Okefenokee Swamp Park by using “prescribed burns.”

[Above photo by Georgia DOT]

The closely monitored burn occurred in 2022 during the winter on roadside right-of-way and mimics nature’s own cycle of rejuvenation. It’s also the first time Georgia DOT has used a prescribed burn to manage vegetation in this way.

The agency noted that such prescribed burns are conducted under strict safety regulations and in partnership with the Georgia Forestry Commission and the Georgia Department of Natural Resources.

The Georgia DOT added in a blog post that the Okefenokee National Wildlife Refuge in Sou​theast Georgia is a vast, mysterious wilderness of bogs, forests and swampy prairies, home to wild species that evoke fauna and flora of primeval times. Rare carnivorous plants like the Sarracenia, or “Pitcher Plant,” entrap insects and use digestive enzymes to dissolve prey.

[Editor’s note: A 2021 episode of the Environmental Technical Assistance Program or ETAP Podcast featured Matthew Quirey – a  landscape design and research fellow with The Ray – discussing how roadside landscapes, more often termed the “right-of-way,” are now being viewed as “habitat assets” instead of maintenance burdens among state departments of transportation.]

Okefenokee – a 438,000-acre wetland that is the largest blackwater wetland in North America – draws around 100,000 visitors from around the globe each year.

To reach its entrance, visitors must travel along a four-mile stretch of SR 177 that is becoming a Georgia DOT living laboratory for innovative vegetative management practices designed to protect plants in the environmentally sensitive area while simultaneously ensuring public safety.

The agency has been involved in a number of plant and pollinator support efforts in recent years.

For example, in 2021, Georgia DOT the Georgia Association of Conservation Districts or GACD installed 15 pollinator habitat sites in designated locations as part of a joint effort to educate state residents about the important role “pollinators” such as bees, butterflies, and other insects play in Georgia’s agricultural sector.

Minnesota Study Examines Post-Project ‘Revegetation’ Efforts

A team of University of Minnesota researchers recently wrapped up a study that examined the effectiveness of “revegetation” efforts following the conclusion of infrastructure projects statewide. That study also compiled “best practice” recommendations to transportation departments and roadside management organizations regarding post-project efforts to create pollinator-friendly habitats.

[Above photo by the Minnesota DOT]

The study – sponsored by the Minnesota Department of Transportation and the Minnesota Local Road Research Board – examined how transportation agencies “revegetate” roadsides after construction projects to provide road stability, storm water filtration, and visual appeal. Revegetation is also a good opportunity to create pollinator-friendly habitat. However, planting and maintaining ditches can be expensive, funds for such projects are usually limited, and there isn’t much data on which methods actually work, the researchers found.

“This project will help agencies across the state refine the seed mixes they use with substantial benefits to pollinator habitat,” noted Dan MacSwain, natural resource coordinator for Washington County Public Works and the technical liaison for this project, in a blog post. “It will also produce cost savings.”   

A key part of the study measured the presence of bumblebees and flowers in roadside ditches and generally found a positive link between the two – suggesting that greater flower diversity promotes stronger pollinator populations. That portion of the study also found that bumblebees are more prolific in roadside ditches where the surrounding landscape is also pollinator-friendly; suggesting that ditches alone cannot fully meet the habitat needs of insects, Snell-Rood emphasized, meaning roadside restoration efforts can generally perform better if they’re located near already-established pollinator habitat.

The insects that the survey studied – bumblebees and butterflies – showed a ready willingness to use non-native flowers for food. However, the study also points out that these insect groups are “generalists” and this amenable to feeding on a wide variety of flowering plants. That means revegetating ditches with non-native plants will not support more specialized pollinators – ones that need specific, native flowers to survive, the researchers found.

“Our results suggest that roadsides could be managed with a ‘more flowers everywhere’ strategy without raising costs,” added Emilie Snell-Rood, associate professor with the University of Minnesota’s Department of Ecology, Evolution, and Behavior and the principal investigator for the project. “[However] the ‘set it and forget it’ approach to native roadside revegetation efforts is insufficient if long-term establishment of native plants is the goal.”

For generalized, pollinator-friendly revegetation practices, the researchers recommended using an inexpensive, non-native seed mix – such as alfalfa, red clover, or white clover – mixed in with a handful of native species proven to be good at establishing themselves, such as wild bergamot, field thistle, goldenrod, and common milkweed. However, if the goal is to conserve a particular species, the roadside will need to be tailored to that species’ plant food needs.

“Our results overall suggest roadside management for natives and pollinators requires some discussions within agencies and management organizations about primary goals,” Snell-Rood said.

State departments of transportation across the country have been heavily involved in a wide array of pollinator specie preservation and growth efforts over the years.

For example, in 2021, the Georgia Department of Transportation and the Georgia Association of Conservation Districts installed 15 pollinator habitat sites in designated locations as part of a joint effort to educate state residents about the important role “pollinators” such as bees, butterflies, and other insects play in Georgia’s agricultural sector.

Out west, the Texas Department of Transportation has been working for several years to make the state’s bridges and related infrastructure more hospital to bats, especially as the nocturnal flying rodents help to naturally suppress the insect population without the use of pesticides while acting as pollinators to assist in flowering plant reproduction.

Meanwhile, the Tennessee Department of Transportation, along with the Tennessee Department of Environment & Conservation and Tennessee Department of Agriculture, formed a partnership in 2019 to support 64 acres of “pollinator meadows” at eight state parks. Each blooming meadow contains a mix of nectar-bearing plants and milkweed, which sustain pollinators such as bees, moths, butterflies, birds, and small mammals such as bats.

And in in March 2020, the American Association of State Highway and Transportation Officials sent a two-page letter to the U.S. Department of the Interior supporting “expedited approval” of the voluntary national Candidate Conservation Agreement with Assurances or CCAA to further encourage the creation of pollinator habitats in highway rights-of-way.

The CCAA – eventually finalized in April 2020 – provides a “huge boost” for the conservation of Monarch butterflies and other pollinators on a landscape scale, the U.S. Fish & Wildlife Service noted at the time.

ETAP Podcast: Oregon DOT Discusses Wildlife Crossings

In this episode of the Environmental Technical Assistance Program or ETAP Podcast, Cidney Bowman (above) – wildlife passage program coordinator for the Oregon Department of Transportation – discuss the different types of projects deployed by the agency to help prevent wildlife-vehicle collisions while at the same time improving habitat connectivity.

[Above photo by the Oregon DOT]

The ETAP podcast – a technical service program for state departments of transportation provided by the American Association of State Highway and Transportation Officials – explores a wide array of environmental topics that affect transportation and infrastructure programs.

During this month’s podcast, Oregon DOT’s Bowman also digs into what the U.S. Department of Transportation calls a “first-of-its-kind” pilot program that makes $350 million available over the next five years.

That includes more than $111 million in grants through its first round of funding in 2023, to support projects that prevent wildlife-vehicle collisions and improve habitat connectivity on a national basis.

[Editor’s note: In the video below, Bowman explains how wildlife undercrossings improve safety for animals and motorists alike.]

That federal funding supports both construction and non-construction projects, Oregon DOT noted – covering research, planning, and design endeavors that increase animal safety on roads.

Wildlife-vehicle collisions represent a major challenge across the country, according to USDOT data, totaling roughly 1 million to 2 million large animal impacts per year, which injure 26,000 people, cause 200 deaths, and results in $8 billion in property damage.

Oregon DOT has successfully enacted a variety of wildlife-collision prevention projects over the past several years, which reduced wildlife-vehicle collisions statewide by 86 percent

To listen to this podcast, click here.

NCDOT Highway Right-of-Ways Win Wildflower Awards

Each year, awards sponsored by The Garden Club of North Carolina are given to the best-looking flower beds along highways in every region of the state – awards that recognize the efforts of North Carolina Department of Transportation staff who carry out the agency’s wildflower program, which for 37 years has enhanced the overall appearance and environmental quality of North Carolina’s highways.

[Above photo by NCDOT]

The 2022 Wildflower Awards were presented to NCDOT teams during the April Board of Transportation meeting by NCDOT Roadside Environmental Engineer David Harris. And a Flickr album with photos of the winners is available here.  

“Our wildflower beds wouldn’t be successful without the hard work put in by our staff. Their commitment to creating detailed flower beds for everyone to enjoy deserves every recognition,” he explained in a statement. “The Wildflower Program is a long-lasting initiative, and we can’t wait to see the beautiful blooms that are due to grow in 2023.”

State DOTs across the country are not only involved in a variety of wildflower- and pollinator-support efforts, many also use special teams to help preserve native animals and plants during infrastructure projects, which also in some cases using natural vegetation to aid in safety projects, such as the construction of snow fences.

On the pollination side, in October 2021 the Georgia Department of Transportation and the Georgia Association of Conservation Districts or GACD began installing 15 pollinator habitat sites in designated locations as part of a joint effort to educate state residents about the important role “pollinators” such as bees, butterflies, and other insects play in Georgia’s agricultural sector.

“This partnership provides Georgia DOT with the unique opportunity to create a safe and beautiful place for families and travelers to get up close and personal with the wildflowers and grasses [to] learn about how they impact the world around us,” explained Felicity Davis, a landscape architect manager with the Georgia DOT.

“We carefully considered the locations for these gardens and with pedestrian safety in mind, we determined the best option would be at rest areas and Welcome Centers across the state,” she said.

Meanwhile, in March 2022, the Minnesota Department of Transportation began “rejuvenating” seven so-called “living snow fences” in southwest Minnesota as part of a month-long effort to ensure the 20-year-old plantings can survive for another two decades. The agency noted that a “living snow fence” is comprised of trees, shrubs, native grasses, and/or wildflowers to trap snow as it blows across fields, piling it up before it reaches a bridge or roadway.

“A living snow fence is more than landscaping and highway beautification, it serves a purpose,” explained Dan Gullickson, Minnesota DOT’s blowing snow control shared services program supervisor. “We use nature to control blowing snow and rejuvenating these living snow fence sites will safeguard the health and vitality of the plantings.”

Where native plant preservation is concerned, the Arizona Department of Transportation uses “biomonitor” teams from Northern Arizona University or NAU to help the agency’s work crews find and relocate endangered species – including snakes, birds and fish – from construction sites.

Specifically, the biomonitor teams train construction workers and other involved in transportation projects to identify any endangered species and what to do if they come across one. The teams also monitor construction activity and help safely remove any endangered species out of harm’s way.

USDOT Initiates Wildlife-Vehicle Collision Prevention Project

The U.S. Department of Transportation recently began what it calls a “first-of-its-kind” pilot program to prevent wildlife-vehicle collisions and improve habitat connectivity.

[Above photo by the Colorado DOT]

Created and funded by the $1.2 trillion Infrastructure Investment and Jobs Act or IIJA enacted in November 2021, that pilot program – dubbed the “Wildlife Crossings Pilot Program” and managed by the Federal Highway Administration – will make grant funding available to states and communities to construct wildlife crossings over or below busy roads, add warning signs for drivers, acquire mapping and tracking tools, and more.

FHWA is making a total of $350 million available over five years, including more than $111 million in grants through its first round of funding in 2023. The agency also noted that roughly 200 people are killed – and many more are injured – annually in the United States in more than one million collisions involving wildlife and vehicles.

“There are proven practices to prevent crashes between vehicles and wildlife, and with this investment, we’re going to take commonsense steps to reduce collisions and make roads safer for rural and urban communities alike,”FHWA Administrator Shailen Bhatt said in a statement.

“Communities that may not previously have had access to funding for these critical projects can finally make roads safer while protecting wildlife and their movement corridors,” he added.

FHWA noted that grants are available for all wildlife-vehicle collision prevention activities, including but not limited to research, planning, design, and construction.

The agency added that it seeks to award funds for both non-construction and construction projects via the new program, including research on safety innovations, mapping and tracking tools, and the design and construction of overpasses and underpasses.

A recent blog post by the Pew Trusts highlights how the growing success of wildlife crossings – bridges, underpasses, and culverts designed to help animals avoid vehicle traffic – across the U.S. is drawing a surge of interest from policymakers seeking to reduce wildlife-vehicle collisions and protect animals.

Meanwhile, state departments of transportation have already been working on a variety of wildlife-vehicle collision prevention initiatives over the last several years.

For example, to date, Colorado DOT said it has built more than 60 wildlife mitigation structures crossing above or under highways throughout the state. Additionally, it has installed 400 miles of high big game fencing along state and U.S. highways or next to the interstates.

In August 2022, the agency completed a wildlife overpass and underpass on U.S. Highway 160 in the southwestern part of the state; a stretch of road where more than 60 percent of all crashes are due to wildlife-vehicle collisions.

In April 2022, the Oregon Department of Transportation received a special one-time allocation of $7 million in general funds from the Oregon legislature to invest in wildlife corridor projects statewide.

The Oregon DOT said it has had “great success” with wildlife undercrossing structures in recent years, with five crossings built to date in the state, all on U.S. 97, leading to an 86 percent reduction in wildlife-vehicle collisions.

Concurrently, a research document released in July 2022 by an international pool funded study led by the Nevada Department of Transportation provides an “authoritative review” of the most effective measures to reduce animal-vehicle collisions, improve motorist safety, and build safer wildlife crossings.

Caltrans to Help Build Highway/Rail Wildlife Overpass

The California Department of Transportation, the California Department of Fish and Wildlife (CDFW), and passenger rail provider Brightline West plan to jointly design and construct three wildlife overcrossings across Interstate 15 and the future Brightline West high-speed rail system connecting Las Vegas and Southern California.

[Above photo by Caltrans]

Those overcrossings seek to provide a sustainable and safe path for wildlife – especially for bighorn sheep – over the existing northbound and southbound highway lanes and the future 218-mile high-speed rail system to be built within the median, explained California Governor Gavin Newsom (D).

“Roadways and rail lines must be designed to connect, not divide,” he said in a statement. “This project will not only protect the precious wildlife and habitat of the Mojave Desert region but will also get people between Las Vegas and Southern California safely and efficiently – preserving one of the most popular corridors in our state.”

Beyond building those three wildlife overcrossings, the Brightline West project aims to maintain or improve more than 600 culverts and large-scale crossings under I-15 that exist today as well as restore and install desert tortoise fencing and directional wildlife exclusionary fencing.

Over the past year, Brightline, Caltrans and CDFW said they have worked together to develop a coordinated plan to fund, design, construct and maintain these wildlife overcrossings. The parties intend to fund the overcrossings using a mix of Caltrans, CDFW and Brightline West capital resources, while also seeking federal dollars.

Concurrently, a recent blog post by the Pew Trusts highlights how the growing success of wildlife crossings – bridges, underpasses, and culverts designed to help animals avoid vehicle traffic – across the U.S. is drawing a surge of interest from policymakers seeking to reduce wildlife-vehicle collisions and protect animals.

State departments of transportation across the country continue investing in a variety of wildlife crossing projects.

For example, to date, Colorado DOT said it has built more than 60 wildlife mitigation structures crossing above or under highways throughout the state. Additionally, it has installed 400 miles of high big game fencing along state and U.S. highways or next to the interstates.

In August 2022, the agency completed a wildlife overpass and underpass on U.S. Highway 160 in the southwestern part of the state; a stretch of road where more than 60 percent of all crashes are due to wildlife-vehicle collisions.

Meanwhile, a research document released in July 2022 by an international pool funded study led by the Nevada Department of Transportation provides an “authoritative review” of the most effective measures to reduce animal-vehicle collisions, improve motorist safety, and build safer wildlife crossings.

With as many as two million collisions with large mammals in the United States leading to approximately 200 human deaths every year, the review compiled, evaluated, and synthesized studies, scientific reports, journal articles, technical papers, and other publications from within the United States and beyond to determine effectiveness of 30 different mitigation measures.