Western Transportation Institute

Permanent URI for this communityhttps://scholarworks.montana.edu/handle/1/35

The Western Transportation Institute is the country's largest National University Transportation Center focused on rural transportation issues. Because we live and work in rural communities, we understand the critical roles rural transportation plays in the lives of people, in the environment and in the economy. We draw from our eight integrated research groups to create solutions that work for our clients, sponsors and rural transportation research partners. WTI focuses on rural issues, but some of our program areas also address the concerns of the urban environment. Whatever the objective, we bring innovation and expertise to each WTI transportation research project. WTI's main facility with its state-of-the-art labs is adjacent to the Montana State University campus in Bozeman, Montana. We have additional offices in Alberta, Canada, and central Washington, and a large testing facility in rural Montana near Lewistown. Contact us to find out how to address your rural transportation research needs.

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10 Steps to Implementing Health in All Policies in Rural Communities
(Western Transportation Institute, 2024-08) Comey, Danika; Madsen, Matthew
This toolkit serves as a guiding document for frontier, rural, and micro-urban communities to implement a Health in All Policies (HiAP) framework in rural America. Too often, rural America is overlooked when it comes to public health and policy work. This tool will guide public health practitioners, community planners, elected officials, healthcare providers, and those who are interested in improving community and public health by analyzing and improving local policy in rural communities. Barriers to accessing healthcare services are well documented in rural communities. Rural populations often face greater challenges accessing healthcare services compared to their urban peers such as long distances to primary care, lower insurance coverage rates, higher health needs, and higher rates of poverty [1–4]. Incorporating a HiAP framework in rural areas is an effective way to decrease health inequities and disparities between urban and rural communities.
Analyze Business Models for Implementation and Operation of a Statewide GNSSRTN
(Montana Department of Transportation (SPR), 2022-10) Al-Kaisy, Ahmed; Teixeira, Rafael; Raza, Sajid; Meyer, Benjamin
The Global Navigation Satellite System (GNSS), commonly known as the global positioning system, has become one of the fastest growing emerging technologies delivering location services to various sectors. The applications of geospatial data span every sphere of modern-day science and industry where geographical positioning matters. The list includes navigation, agriculture, surveying, construction, transportation, forestry, mining, and many others. The accuracy and precision of geospatial data using the GNSS Real-Time Network (RTN) technology enable advanced applications in many fields where geospatial data is used; and open the doors for new applications such as the emerging autonomous systems in transportation, mining, and agriculture. This research project is intended to provide information that would help the state’s efforts in the planning and implementation of the Montana GNSS-RTN system. Four major tasks were completed for this project, namely; state-of-the-art review, state-of-the-practice assessment, characterizing Montana existing GNSS-RTN infrastructure, and identifying and cataloging viable business models for statewide GNSS-RTN systems.
Animal Vehicle Collision Reduction and Habitat Connectivity Cost Effective Solutions - Final Report
(Nevada Department of Transportation, 2022-07) Ament, Rob; Huijser, Marcel; May, Dana
Wildlife-vehicle collisions (WVCs) are a significant component of overall crashes in the US and Canada. Roads and their traffic also create partial or total barriers to the movement of wildlife, both large and small. There are several well-studied proven mitigation measures that significantly reduce WVCs, provide for safe animal passage across roads, and maintain habitat connectivity. Highly effective measures, such as overpasses and underpasses with fencing can reduce large animal WVCs by over 80% – 100% on average; yet these structures can be costly and there is room for improvement in their design, the use of new materials, adding elements that improve their use by smaller animal species, such as reptiles and amphibians and improving their cost effectiveness. This Transportation Pooled Fund Study, TPF-5(358) (TPF Study), allowed researchers to evaluate the latest information on the effectiveness of 24 different highway mitigation measures designed to decrease collisions with large wildlife, large feral and domestic animals. Also reviewed were these same measures’ ability to protect small mammals, reptiles, and amphibians from collisions. The TPF Study also explored the effectiveness of the 24 measures ability to maintain or enhance habitat connectivity. It conducted 11 different research projects that variously explored a) the costs and benefits of animal-vehicle collisions and the mitigation measures that seek to reduce them, b) the ecological effectiveness of various mitigation measures, and 3) new designs for crossing structures for a variety of species. The project developed a manual of best practices and concluded with a final report.
Animal Vehicle Collision Reduction and Habitat Connectivity Pooled Fund Study – Literature Review
(Nevada Department of Transportation, 2021-12) Huijser, M.P.; Ament, Robert J.; Bell, M.; Clevenger, A. P.; Fairbank, E.R.; Gunson, K.E.; McGuire, T.
This report contains a summary of past research and new knowledge about the effectiveness of mitigation measures aimed at reducing animal-vehicle collisions and at providing safe crossing opportunities for wildlife. The measures are aimed at terrestrial large bodied wild mammal species, free roaming large livestock species (e.g. cattle, horses), free roaming large feral species (e.g. “wild” horses and burros), and small animal species (amphibians, reptiles, and small mammals). While mitigation is common, it is best to follow a three-step approach: avoidance, mitigation, and compensation or “off-site” mitigation. If reducing collisions with large wild mammals is the only objective, the most effective measures include roadside animal detection systems, wildlife culling, wildlife relocation, anti-fertility treatments, wildlife barriers (fences),and wildlife fences in combination with wildlife crossing structures. If the objectives also include maintaining or improving connectivity for large wild mammals, then wildlife barriers (fences) in combination with wildlife crossing structures are most effective. Measures for large domestic mammal species are largely similar, though for free roaming livestock there are legal, moral and ethical issues. For small animal species, temporary or permanent road closure and road removal are sometimes implemented, but barriers in combination with crossing structures are the most common.
Bees and Butterflies in Roadside Habitats: Identifying Patterns, Protecting Monarchs, and Informing Management
(ITD Reseach Program, 2023-07) Meinzen, Thomas C.; Debinski, Diane M.; Burkle, Laura A.; Ament, Robert J.
Pollinating insects provide vital ecosystem services and are facing global declines and habitat loss . Roadsides are increasingly regarded as important potential areas f or enhancing pollinator habitat. Understanding which roadsides best support pollinators — and why — is essential to helping locate and prioritize pollinator conservation efforts across roadside networks. To support this effort, we assessed butterfly, bee, and flowering plant species richness and abundance on a set of 63 stratified randomized roadside transects in State-managed rights-of-way in SE Idaho. Our research evaluated pollinator diversity as a function of highway class (interstate, U.S., and state highways), remotely sensed NDVI values (a measure of vegetation greenness), and floral resources. We found that smaller highways and lower (less green) maximum NDVI values were associated with significantly more bee species and total bees. Roadsides bordering sagebrush habitats typically had low NDVI values and higher bee and butterfly species richness, potentially contributing to this observed pattern. Butterfly richness increased in association with higher floral abundance in roadsides. Additionally, we identified and mapped 1,363 roadside patches of milkweed (Asclepias speciosa), larval host plant for the imperiled monarch butterfly (Danaus plexippus), in a survey of over 900 miles of southern Idaho highways. Based on these results and a literature review, we recommend management strategies to promote the health of pollinator populations in Idaho’s rights-of-way and provide data to help ITD prioritize areas for pollinator-friendly management practices and habitat restoration within their highway system.
A before-after-control-impact study of wildlife fencing along a highway in the Canadian Rocky Mountains
(Nevada Department of Transportation, 2022-02) Clevenger, Anthony P.; Ford, Adam T.
Wildlife exclusion fencing has become a standard component of highway mitigation systems designing to reduce collisions with large mammals. Past work on the effectiveness of exclusion fencing has relied heavily on control-impact (i.e., space-for-time substitutions) and before-after study designs. These designs limit inference and may confound the effectiveness of mitigation with co-occurring process that also change the rate of collisions. We used a replicated before-after-control-impact study design to assess fencing effectiveness along the Trans-Canada Highway in the Rocky Mountains of Canada. We found that collisions declined for common ungulates species (elk, mule deer and white-tailed deer) by up to 96% but not for large carnivores. The weak response of carnivores is likely due to combination of fence intrusions and low sample sizes. When accounting for background changes in collision rates observed at control sites, naïve estimates of fencing effectiveness declined by 6% at one site to 90% and increased by 10% at another to a realized effectiveness of 82%. When factoring in the cost of ungulate collisions to society as a whole, fencing provided a net economic gain within 1 year of construction. Over a 10-year period, fencing would provide a net economic gain of >$500,000 per km in reduced collisions. In contrast, control site may take upwards of 90 years before the background rates of collisions decline to a break even point. Our study highlights the benefits of long-term monitoring of road mitigation projects and provides evidence of fencing effectiveness for reducing wildlife-vehicle collisions involving large mammals.
Best Practices Manual to Reduce Animal-Vehicle Collisions and Provide Habitat Connectivity for Wildlife
(Nevada Department of Transportation, 2022-09) Huijser, M.P.; Fairbank, E.R.; Paul, K.S.
The goal for this manual is to provide practical information for the implementation of mitigation measures that aim to: 1. Improve human safety through reducing collisions with large animals, including large wild mammal species, select free roaming large feral species, and select free roaming large livestock species, and 2. Improve or maintain habitat connectivity for terrestrial wildlife species and selected feral species through safe crossing opportunities. This manual does not include all possible measures that can or may reduce animal-vehicle collisions and maintain or improve habitat connectivity for wildlife. The measures included in this manual are: Barriers (fences) in combination with crossing structures (for large wild mammals and for small wild animal species), roadside animal detection system, Barriers (fences), Barriers (fences) in combination with crossing structures (for free roaming livestock), and culling, relocation, anti-fertility treatment, roadside animal detection systems, barriers (fences), and barriers (fences) in combination with crossing structures (for large feral mammal species such as feral horses and burros).
Bicycle & Pedestrian Infrastructure Improvements Realized in Communities of Less Than 10,000 People: Final Report
(2018-12) Villwock-Witte, Natalie
The objective of this study was to better define underlying factors that have allowed communities of less than 10,000 people within three states (Maine, Minnesota, and New Hampshire) to successfully implement bicycle and pedestrian infrastructure. These factors were defined by first conducting a thorough literature review along with general information gathering, as there is little published knowledge about communities of less than 10,000 people. Based on the information collected and synthesized from the literature review, interview questions were developed to ask leadership (planners, town administrators, elected officials) and advocates within communities of less than 10,000 people. Interviewees were targeted from two types of communities: those that have successfully implemented bicycle and pedestrian infrastructure, and those that have shown potential to implement bicycle and pedestrian infrastructure. As an outcome of a series of in-depth interviews with key members in chosen communities, the following characteristics surfaced as being influential in whether or not bicycle and pedestrian infrastructure can be found within these smaller communities within Maine, Minnesota, and New Hampshire: • The speed limits, particularly adherence to speed limits within a community, • Having many champions for bicycle and pedestrian modes, • Having programs to teach or support bicycle and/or pedestrian modes, • Having bicycle and/or pedestrian groups, and • The community approval process.
A comparison of elk-vehicle collisions patterns with demographic and abundance data in the Central Canadian Rocky Mountains
(Nevada Department of Transportation, 2021-09) Gunson, Kari E.; Clevenger, Anthony P.; Ford, Adam T.
This study looks at the patterns and processes of elk-vehicle collisions in the Central Canadian Rocky Mountains and analyses the demographic structure of the wildlife involved in the collisions. Key findings included: males and subadults were more prone to elk-vehicle collisions; collisions occur more commonly in the fall season; all healthy elk are susceptible to vehicle collisions; the magnitude of elk collision was negatively correlated to traffic volumes, because abundance of elk greatly decreased during the study period; and elk abundance was the primary driver influencing occurrence of collisions over time. Collectively, these results will help inform the design of mitigation measures targeting the most vulnerable demographics of a population, i.e. subadults and male elk in the fall.
Economic feasibility of safety improvements on low-volume roads
(2017-09) Al-Kaisy, Ahmed; Ewan, Levi A.; Hossain, Fahmid
This article presents an investigation into the economic feasibility of safety countermeasures along rural low-volume roads. Although these roads may be associated with higher crash risks as they\'re built to meet lower standards, crash frequencies are notably lower than those on other roadways with higher traffic exposure. Therefore, it is reasonable to expect that some conventional safety countermeasures that are proven to be cost effective on well-travelled roads may turn out to be infeasible on low-volume roads. Twenty-seven safety improvements were examined in this investigation for their economic feasibility along low-volume roads. A roadway sample of 681 miles of Oregon was used in this study. Detailed benefit-cost analyses were performed using countermeasure costs, 10-year crash data, and expected crash reductions using Highway Safety Manual methods. Around half of the countermeasures investigated were found cost-effective for implementation along low-volume roads. Further, most of the countermeasures that were found to have very high benefit-cost ratio are associated with low initial cost and many of them do not require much maintenance cost. At the other end of the spectrum, almost all roadway cross-section safety improvements were found economically infeasible due to higher associated costs relative to the expected crash reduction benefits on low volume roads.
The effectiveness of electrified barriers to keep large mammals out of fenced road corridors
(Nevada Department of Transportation, 2022-09) Huijser, M.P.; Getty, S.C.
For this project the researchers investigated the effectiveness of different types of electrified barriers for varying traffic volume and traffic speed. Some barriers were investigated for carnivores only, whereas others were evaluated for both ungulates and carnivores. Finally, we combined the data from our field studies with those reported in the literature and conducted a meta-analysis to investigate the effectiveness of different types and dimensions of barriers for both ungulates and carnivores. In general, electrified barriers can be a substantial barrier to species with paws, including black bears. However, careful maintenance and monitoring is required for these measures to succeed.
Electrified Barriers Installed on Top of Wildlife Guards to Help Keep Large Wild Mammals Out of a Fenced Road Corridor
(Western Transportation Institute, Montana State University, 2023-12) Huijser, M.P.; Getty, S.C.
Most wildlife mitigation measures along highways are aimed at improving human safety, reducing direct wildlife mortality, and providing safe crossing opportunities for wildlife. Fences in combination with wildlife crossing structures are the most effective combination of mitigation measures to achieve these objectives. For fences to reliably reduce collisions with large wild mammals by 80% or more, at least 5 kilometers (3 miles) of road length needs to be fenced, including a buffer zone that extends well beyond the known hotspots for wildlife-vehicle collisions. Collisions that still occur within the fenced road sections tend to be concentrated near the fence-ends. In addition, gaps in fences, including at access roads, can result in concentrations of collisions inside fenced road sections. Gates are commonly used at gaps in the fence at low traffic volume access roads, but they are often left open allowing wildlife to access the road corridor. While cattle guards or wildlife guards can be effective for some ungulate species, double wide cattle or wildlife guards consisting of round bars or bridge grate material, situated above a pit, are generally recommended for ungulates. However, such guards are not a substantial barrier for species with paws, including many carnivore species. Electrified mats or electrified guards can be a barrier for both ungulates and species with paws, but to prevent animals from jumping across the mat, they need to be 4.6-6.6 m (15-22 ft)) wide. For this project, a combination of wildlife guards and electrified barriers on top of these wildlife guards was evaluated. Both electrified mats that were tested (Crosstek and BS Fabrications) on top of existing wildlife guards resulted in a near absolute barrier for both ungulates and species with paws (97.9% barrier for the 2 deer species combined, 100% barrier for coyotes and black bears); an improvement to a wildlife guard only without an electrified mat (89.3% for the 2 deer species combined, 54.5% barrier for coyotes and 45.5% barrier for black bears). Based on the images, there is evidence that a shock is delivered to the animals that touch the electrified mats and that most of the animals respond by returning to the habitat side of the barrier. Specifically for bears, if it was not for the electrified barriers, likely at least 3 black bears and 1 grizzly bear would have crossed into the fenced road corridor where they would have been exposed to vehicles.
An estimate of wild mammal roadkill in Sao Paulo state, Brazil
(Elsevier BV, 2021-01) Abra, Fernanda Delborgo; Huijser, Marcel Pieter; Magioli, Marcelo; Bobo, Alex Augusto Abreu; de Barros Ferrraz, Katia Maria Paschoaletto
Roadkill estimates for different species and species groups are available for many countries and regions. However, there is a lack of information from tropical countries, including from Latin America. In this study, we analyzed medium and large-sized mammal roadkill data from 18 toll road companies (TRC) in São Paulo State (6,580 km of monitored toll roads), Brazil. We extrapolated these roadkill numbers to the entire system of major paved roads in the State (36,503 km). The TRC collected mammal-road- mortality data both before (2-lanes) and after (4-lanes) road reconstruction. We used the “before” data from the TRC to estimate annual mammal-road-mortality along 2-lane roads that remained public roads. Combined with the data for the new 4-lane highways, this allowed us to estimate annual mammal road mortality for all the paved roads in the State. During 10 years of roadkill monitoring along toll roads, a total of 37,744 roadkilled mammals were recorded, representing a total of 32 medium to large-sized mammal species (average number of roadkilled individuals/year = 3,774 ± 1,159; min = 1,932; max = 5,369; 0.6 individuals roadkilled/km/year). Most roadkilled species were common generalists, but there were also relatively high roadkill numbers of threatened and endangered species (4.3% of the data), which is a serious conservation concern. Most of the roadkill was reported occurred during the nocturnal period (66%, n = 14,189) and in the rainy months (October–March) (55%, n = 15,318). Reported mammal roadkill tended to increase between 2009 and 2014 (R2 = 0.614; p = 0.065), with an average increase of 313.5 individuals/year. Extrapolation of the results to the entire São Paulo State, resulted in an average estimate of 39,605 medium and large-sized mammals roadkilled per year. Our estimates of the number of roadkilled individuals can be used as one of the input parameters in population viability analyses to understand the extinction or extirpation risk, especially for threatened and endangered species.
Exploration of opportunities to address the impacts of roads and traffic on wildlife around Rocky Flats National Wildlife Refuge
(Western Transportation Institute, 2023-11) Huijser, Marcel P.; Begley, James S.
Rocky Flats National Wildlife Refuge (“the Refuge”) in Colorado near Denver, Colorado, has a history (1952-1 989) of producing components for nuclear weapons. The current goal for the area is “to restore and preserve the native prairie ecosystems, provide habitat for migratory and resident wildlife, conserve and protect habitat for Preble’s meadow jumping mouse, and provide research and education opportunities”. The grasslands of the Refuge are surrounded by busy roads to the west (Hwy 93, 18,000 AADT), north (Hwy 128, 4,200 AADT) and east (Indiana St. 7,000 AADT), and there are houses and associated roads on its southern boundary. Other open space with non-motorized trails and protected areas with predominantly grassland are to the west, north and east. Large ungulates, including mule deer, elk, and moose cross the roads. This results in large ungulate -vehicle collisions and the roads also represent a barrier to the movements of animals. Creek crossings under the roads are a concern as they are likely a barrier for species dependent on riparian habitat, including the Preble’s meadow jumping mouse. The objectives of the current project were to 1. Formulate measures that reduce collisions with large wild mammals, and 2. Formulate measures that improve connectivity across roads for large wild mammal species and one small mammal species in specific, the Preble’s meadow jumping mouse. We suggest large open span bridges at creek crossings (for deer, moose, black bear, mountain lion, and Preble’s meadow jumping mouse) and designated wildlife overpasses for elk and also f or mule deer. The crossing structures may be combined with human co-use to connect the trails on the refuge with the trail system in the surrounding areas.
Exploring Apex Predator Effects on Wildlife-Vehicle Collisions: A Case Study on Wolf Reintroductions in Yellowstone
(Western Transportation Institute, 2024-09) Bell, Matthew; Huijser, Marcel P.; Kack, David
This study investigates the impact of wolf reintroduction on wildlife-vehicle collisions (WVCs) along a segment of US-191 bordering Yellowstone National Park. Wolves were reintroduced in 1995–1996, and subsequent wolf pack establishment may have influenced the behavior and population dynamics of prey species, potentially altering WVC patterns. Using carcass data collected from 1989 to 2021, the analysis was divided into two primary phases: before wolves (1989–1996) and after wolves (1997–2021). A series of linear mixed-effects models were developed to assess changes in WVCs across these time periods. Predictor variables included average annual daily traffic (AADT), elk population estimates, and wolf counts. Results showed that WVCs significantly declined in the post-wolf period, suggesting that the presence of wolves may reduce WVCs directly by modifying prey behavior and movement patterns, or indirectly by reducing prey population densities. Further analysis revealed that while elk populations were a significant predictor of WVCs before wolves were reintroduced, this relationship weakened post-reintroduction. Traffic volume did not significantly influence WVC patterns in either period, nor did it interact significantly with wolf presence. The inclusion of wolf counts as a continuous variable showed a negative relationship with WVCs, indicating that higher wolf densities may contribute to a further reduction in collisions over time. These findings suggest that apex predators can play a role in mitigating human-wildlife conflicts, such as WVCs, by influencing prey species’ behavior and distribution. The study provides valuable insights for wildlife managers and transportation planners, highlighting the potential benefits of predator conservation for road safety and ecosystem health.
Final Report 2022: Update and expansion of the WVC mitigation measures and their cost-benefit model
(Nevada Department of Transportation, Carson City, NV, 2022-10) Huijser, M.P.; Duffield, J.W.; Neher, C.; Clevenger, A.P.; McGuire, T.
This report contains an update and an expansion of a cost-benefit model for wildlife-vehicle collisions and associated mitigation measures along highways, that was originally calculated in 2007 US$ and published in 2009. The direct cost values (vehicle repair, human injuries, human fatalities) were updated for deer, elk, and moose, and expanded by including additional species: gray wolf (Canis lupus), grizzly bear (Ursus arctos), and free ranging or feral domesticated species including cattle, horse, and burro. The costs associated with collisions were also expanded by including passive use, or nonuse values associated with the conservation value of selected wild animal species. The total costs (in 2020 US$) associated with a collision with deer, elk and moose were about 2-3 times (direct costs only) or about 3-4 times higher (direct costs and passive use values combined) compared to the values in 2007 US$. The passive use costs associated with threatened species (wolf, grizzly bear) were higher or much higher than the direct costs. The costs associated with mitigation measures (especially fences and wildlife crossing structures) were also updated and supplemented with new data. New cost-benefit analyses generated updated or entirely new threshold values for deer, elk, moose, and grizzly bear. If collisions with these large wild mammal species reach or surpass the threshold values, it is economically defensible to install the associated type and combination of mitigation measures, both based on direct use and passive use parameters and their associated values. The trend in increasing costs associated with vehicle repair costs, costs associated with human injuries and fatalities, and through including passive use values for wildlife is that we learn that the implementation of effective mitigation measures can be considered earlier and more readily than based on the cost-benefit model published in 2009.
GNSS-RTN Role in Transportation Applications: An Outlook
(American Society of Civil Engineers, 2022-08) Raza, Sajid; Al-Kaisy, Ahmed; Teixeira, Rafael; Meyer, Benjamin
Geospatial location service is not only used in measuring ground distances and mapping topography, but has also become vital in many other fields such as aerospace, aviation, natural disaster management, and agriculture, to name but a few. The innovative and multi-disciplinary applications of geospatial data drive technological advancement toward precise and accurate location services available in real-time. Although the RTN technology is currently utilized in a few industries such as precision farming, construction industry, and land survey, the implications of precise real-time location services would be far-reaching and critical to many advanced transportation applications. The GNSS real-time network (RTN) technology, introduced in the mid-1990s, is promising in meeting the needs of automation in most of the advanced transportation applications. This article presents an overview of the GNSS-RTN technology, its current applications in transportation-related fields, and a perspective on the future use of this technology in advanced transportation applications.
Identification and prioritization of road sections with a relatively high concentration of large wild mammal-vehicle collisions in Gallatin County, Montana, USA
(2024-09) Huijser, Marcel P.; Bell, Matthew A.
The primary objective of this project is to identify and prioritize the road sections in Gallatin County that have a relatively high concentration of collisions involving large wild mammals. These road sections may then later be evaluated for potential future mitigation measures aimed at 1. Reducing collisions with large wild mammals, and 2. Providing safe passage across roads for large wild mammals, as well as other wildlife species in the area. We acquired the 3 datasets related to large wild mammal-vehicle collisions in Gallatin County: 1. Wildlife-vehicle crash data collected by law enforcement personnel, 2. Carcass removal data collected by road maintenance personnel; and 3. Grizzly bear road mortality data by the U.S. Geological Survey. The carcass removal data and grizzly bear road mortality data were merged into one carcass database. We conducted separate analyses for the crash data and the carcass data. We conducted two different types of analyses to identify and prioritize road sections with the highest number of wildlife-vehicle crashes and carcasses: 1. Kernel Density Estimation (KDE) analysis that identifies road sections with the highest concentration of collisions, and 2. Getis-Ord Gi* analysis identifies road sections that have statistically significant spatial clusters of collisions. There was great similarity between the hotspots identified through the Kernel Density Estimation analyses for 2008-2022 and 2018-2022 for both the crash and carcass removal data. The same was true for the Getis-Ord Gi* analyses. Especially sections of I-90 and US Hwy 191 between I-90 through Four Corners to the mouth of Gallatin Canyon had the highest concentration of wild animal crashes and large wild animal carcasses. Based on the Getis-Ord Gi* analyses, these road sections generally had concentrations of crashes and carcasses that were significantly higher than expected should the crashes and carcasses have been randomly distributed. In other words, these road sections do not only have the highest concentration of crashes and carcasses, but the identification of these road sections is not based on coincidence. These road sections have a concentration of crashes and carcasses that is beyond random.
Implementing wildlife fences along highways at the appropriate spatial scale: A case study of reducing road mortality of Florida Key deer
(Pensoft Publishers, 2022-03) Huijser, Marcel P.; Begley, James S.
Florida Key deer mortality data (1966–2017) showed that about 75% of all reported deer mortalities were related to collisions with vehicles. In 2001–2002, the eastern section of US Hwy 1 on Big Pine Key (Florida, USA) was mitigated with a wildlife fence, 2 underpasses, and 4 deer guards. After mitigation, the number of reported Key deer road mortalities reduced substantially in the mitigated section, but this was negated by an increase in collisions along the unmitigated section of US Hwy 1 on Big Pine Key, both in absolute numbers and expressed as a percentage of the total deer population size. The data also showed that the increase in Key deer collisions along the unmitigated highway section on the island could not be explained through an increase in Key deer population size, or by a potential increase in traffic volume. The overall Key deer road mortality along US Hwy 1 was not reduced but was moved from the mitigated section to the nearby unmitigated section. Thus, there was no net benefit of the fence in reducing collisions. After mitigation, a significant hotspot of Key deer-vehicle collisions appeared at the western fence-end, and additional hotspots occurred further west along the unmitigated highway. Exploratory spatial analyses led us to reject the unmitigated highway section on Big Pine Key as a suitable control for a Before-After-Control-Impact (BACI) analysis into the effectiveness of the mitigation measures in reducing deer-vehicle collisions. Instead, we selected highway sections west and east of Big Pine Key as a control. The BACI analysis showed that the wildlife fence and associated mitigation measures were highly effective (95%) in reducing deer-vehicle collisions along the mitigated highway section. Nonetheless, in order to reduce the overall number of deer-vehicle collisions along US Hwy 1, the entire highway section on Big Pine Key would need to be mitigated. However, further mitigation is complicated because of the many buildings and access roads for businesses and residences. This case study illustrates that while fences and associated measures can be very effective in reducing collisions, wildlife fences that are too short may result in an increase in collisions in nearby unmitigated road sections, especially near fence-ends. Therefore it is important to carefully consider the appropriate spatial scale over which highway mitigation measures are implemented and evaluated.
Improving Connectivity: Innovative Fiber-Reinforced Polymer Structures for Wildlife, Bicyclists, and/or Pedestrians
(Nevada Department of Transportation, 2022-09) Bell, Matthew; Ament, Rob; Fick, Damon; Huijser, Marcel
Engineers and ecologists continue to explore new methods and adapt existing techniques to improve highway mitigation measures that increase motorist safety and conserve wildlife species. Crossing structures, overpasses and underpasses, combined with fences, are some of the most highly effective mitigation measures employed around the world to reduce wildlife-vehicle collisions (WVCs) with large animals, increase motorist safety, and maintain habitat connectivity across transportation networks for many other types and sizes of wildlife. Published research on structural designs and materials for wildlife crossings is limited and suggests relatively little innovation has occurred. Wildlife crossing structures for large mammals are crucial for many highway mitigation strategies, so there is a need for new, resourceful, and innovative techniques to construct these structures. This report explored the promising application of fiber-reinforced polymers (FRPs) to a wildlife crossing using an overpass. The use of FRP composites has increased due to their high strength and light weight characteristics, long service life, and low maintenance costs. They are highly customizable in shape and geometry and the materials used (e.g., resins and fibers) in their manufacture. This project explored what is known about FRP bridge structures and what commercial materials are available in North America that can be adapted for use in a wildlife crossing using an overpass structure. A 12-mile section of US Highway 97 (US-97) in Siskiyou County, California was selected as the design location. Working with the California Department of Transportation (Caltrans) and California Department of Fish and Wildlife (CDFW), a site was selected for the FRP overpass design where it would help reduce WVCs and provide habitat connectivity. The benefits of a variety of FRP materials have been incorporated into the US-97 crossing design, including in the superstructure, concrete reinforcement, fencing, and light/sound barriers on the overpass. Working with Caltrans helped identify the challenges and limitations of using FRP materials for bridge construction in California. The design was used to evaluate the life cycle costs (LCCs) of using FRP materials for wildlife infrastructure compared to traditional materials (e.g., concrete, steel, and wood). The preliminary design of an FRP wildlife overpass at the US-97 site provides an example of a feasible, efficient, and constructible alternative to the use of conventional steel and concrete materials. The LCC analysis indicated the preliminary design using FRP materials could be more cost effective over a 100-year service life than ones using traditional materials.