Road Mortality Research Articles

Association of Nighttime Heat with Road Mortality: A Time-stratified Case-crossover Study

Association of Nighttime Heat with Road Mortality: A Time-stratified Case-crossover Study

Administrating first aid in road traffic accidents in Bulgaria: a cross-sectional study

Abstract Background Bulgaria had the highest road mortality rate among European Union members in 2023, having previously ranked second after Romania. Research has consistently demonstrated that prompt pre-hospital care can significantly reduce the adverse effects of road traffic accidents. Thus, we conducted a cross-sectional study to explore the involvement of trained road traffic casualties and bystanders in administering first aid. Methods The study, carried out between April and December 2021, collected data via an online survey administered to members of the Scientific and Academic Cooperation Council by the State Agency Road Safety. The survey encompassed a range of topics, including first aid training, involvement in traffic accidents, behaviour of bystanders, administration of first aid, and sociodemographics. Results Among the 292 respondents, a sizeable proportion (90%) reported having received first aid training. Of these, 35.1% (95% CI 29.2-41.1%; p < 0.001) had personally experienced a road traffic accident, and 64.5% (95% CI 58.1-70.1%; p < 0.001) had witnessed one. It is noteworthy that a fifth of those involved in accidents had employed the skills acquired from first aid training, which included applying a dressing to a wound, bleeding control, and immobilising a fracture. Correspondingly, an equivalent percentage of bystanders administrated aid, with the majority of them performing basic airway management. However, the findings revealed that a significant proportion of participants (79.3%) did not engage in providing first aid. The primary rationale stated was the assessment that it was nonessential. Conclusions Despite the growing road safety challenges and many respondents witnessing or being involved in accidents, only a quarter of those trained in first aid actually provided assistance. Considering the increasing number of deaths and severe injuries, it is crucial to assess the need for frequent first aid training and the population’s proficiency in first aid. Key messages • Bystanders’ competence in administrating first aid can mitigate the adverse effects of road traffic accidents. • Among other road safety measures, investments in first aid training can be beneficial in reducing fatalities and severe injuries.

Notes on Günther’s Oriental Slender Snake (<i>Trachischium guentheri</i>) from the Himalayan Realm of North Sikkim, India

The Indian Himalayan Region (IHR) is known for its biodiversity, yet it faces substantial threats fromanthropogenic activities and climate change. Despite the ecological importance of the IHR, herpetofaunal studies,especially in the eastern Himalayan State of Sikkim, remain limited. We herein address aspects of natural history ofa fossorial snake, Günther’s Oriental Slender Snake (Trachischium guentheri) in North Sikkim. We encountered 25snakes during field surveys from 30 September to 12 October 2023 in the Lachen region at elevations of 2,549–2,918m asl. Responses of snakes to unusually high rainfall led to increased road mortality during the peak tourist season. Inresponse, we propose two specialized structures, featuring elevated barriers and elaborate hollow, trapezoidal concreteslabs, to mitigate roadkills. We also emphasize the importance of monitoring to identify areas with high traffic wheremeasures to mitigate road mortality should be employed.

Introducing a Novel Initiative for Mitigating the Impacts of Road Mortality on Turtles in Brampton, Ontario Using 3D Printed Models: A One Health Perspective

With 7 out of 8 turtle species in Ontario classified as at-risk, vehicular-reptile collisions on roads pose a serious threat to turtle populations provincially. These species, however, play crucial roles in maintaining the health of humans, non-human animals, and the environment. By providing ecosystem services like nutrient cycling, population control, and pollination, turtles are essential in semi-aquatic ecosystems like wetlands. However, the need for road infrastructure to support human populations, failures in exclusion fencing and eco-passages, and the varied perspectives of numerous stakeholders make this issue particularly difficult to solve. Despite these challenges, a novel initiative taking place at Heart Lake Conservation Area in Brampton, Ontario may provide an alternative solution. Using 3D printed models, Toronto and Region Conservation Authority (TRCA), in partnership with the Brampton Library and Heart Lake Turtle Troopers, is attempting to reduce mortality along roads by leveraging knowledge about the nesting preferences of female turtles. From a One Health perspective, this novel initiative engages multiple stakeholders to create an interdisciplinary solution combining technology, art, and science to protect turtle populations in the region.

The integrated methodology for assessing the safety of the road network infrastructure in Romania.

Abstract Romania has the highest road fatality rate in the EU and the lowest perception of road quality. This study presents the implementation of a preliminary procedure and tools provided by the European Commission for the safety assessment of the DN2-E85 road infrastructure, which covers 472.23 km. This road was selected due to the high number of road deaths between 2017 and 2022. The research focuses on the application of both proactive and reactive methodologies as required by Directive (EU) 2019/1936, which requires full road network safety assessments by 2024, with subsequent assessments every five years. The proactive methodology assesses the built-in road safety of the road infrastructure based on design parameters, while the reactive methodology is based on historical data on accidents and traffic flows. The integration of these methodologies allows the classification of road segments into five risk levels. Preliminary results indicate that approximately 59% of the length of the DN2-E85 road is classified as “very high priority”, highlighting significant safety deficiencies, which require actions to immediately improve traffic safety. This study highlights the need for systematic road infrastructure safety assessments and prioritisation of high-risk segments to reduce road fatalities and improve overall road safety. The findings serve as crucial information for road safety auditors and the Romanian Road Authority - ARR, supporting the identification of high-risk areas and the allocation of resources to improve safety. In addition, this research provides a basic basis for future adaptations of road infrastructure safety assessment guidelines, considering the specific characteristics of national and county roads. By aligning with EU directives and national standards, the study aims to increase road safety and reduce the incidence of serious accidents in Romania. The insights gained from this research are essential for developing effective road safety strategies and implementing remedial measures that address the most dangerous segments of the road network.

Nighttime Heat and Road Mortality: A Time-stratified Case-crossover Study

Nighttime Heat and Road Mortality: A Time-stratified Case-crossover Study

Small Endemic Birds and Hot Climate: Avian and Environmental Predictors of Avifauna Road Mortality in Santa Cruz Galapagos

In the Galapagos Islands, the main road in Santa Cruz is one of the elements involved in bird road mortality along with vehicles and the impacted species. This study reports the number of roadkilled birds found on the road from the Itabaca Channel to Puerto Ayora, and the main factors, whether avian or environmental, involved in bird roadkill mortality. We collected individual carcasses in 2004, 2005, 2006, and 2018 with a prevalence of 278, 252, 265, and 294, respectively, across 21 species. The endemic Yellow Warbler Setophaga petechia aureola was the most affected bird. We used a PRIDIT model to rank the top avian and environmental predictors of road mortality. We found that for the sampled years, bird body size (i.e., 8–35 g) and the endemism status (i.e., endemic/native) were the main predictors of roadkill mortality, along with seasonality (i.e., hot season). Weaker predictors related to the bird (i.e., age and sex) and the environment (ecosystem, road slope, vegetation, or precipitation) are also reported as determinants of roadkill mortality. This study on avian mortality aims to inform conservation strategies to reduce the rate of wildlife avian roadkill on Santa Cruz Island and other islands with similar problems.

Road mitigation structures designed for Texas ocelots: Influence of structural characteristics and environmental factors on non-target wildlife usage.

Roads negatively impact wildlife through habitat fragmentation, loss of habitat connectivity, and wildlife-vehicle collisions, thus road mitigation structures, such as wildlife crossing structures (WCS), wildlife guards (WG), and fencing are commonly used to address this issue all over the world, including in the United States. In South Texas, such structures were built or modified along a State Highway in an effort to address road mortality for the endangered ocelot (Leopardus pardalis) and non-target wildlife species. The goal of this study was to examine temporal changes in wildlife interactions with WCS and WG during and after their construction and modification along a South Texas highway and to determine whether environmental factors influenced use of WCS. Using camera traps deployed to monitor the road mitigation structures, we compared crossing rates, repel rates, and species richness of all species that interacted with the structures, and we examined whether differential wildlife use of WCS and WG was affected by one or more structural dimensions, distance to nearby vegetation, and water presence. Crossings through WCS by wildlife decreased following the completion of construction of mitigation structures; however, repel interactions at WG increased. Overall, crossings decreased at WCS that had higher openness ratios and during periods of precipitation and higher daily temperatures, but distance to vegetation had minimal influence. These factors were shown to influence crossings of each of the five most frequently observed species differently. Lastly, the presence of pooled water at one WCS caused a decrease in crossings when the water level was highest but was not a barrier at lower water levels. By examining influences on wildlife interaction with road mitigation structures, we conclude that a variety of structures, including different WCS configurations, can be beneficial in facilitating movement and restricting entry into the right-of-way for a diversity of wildlife species beyond the target species.

Anthropogenic, environmental and temporal associations with vertebrate road mortality in a wildland-urban interface of a biodiverse desert ecoregion.

Road mortality adversely affects wildlife populations. As urbanization and infrastructure densities expand, transportation and wildlife management aim to mitigate wildlife-vehicle conflicts while conserving biodiversity. Roadways in aridland ecosystems can invariably and adversely impact wildlife differently from temperate and other biomes, yet these rapidly urbanizing regions are understudied as are urban-rural gradients. We conducted road-cruise surveys (n = 204; 2018-2023) to assess anthropogenic, environmental, and temporal factors associated with vertebrate roadkill across the wildland-urban interface of Arizona's biodiverse Sonoran Desert ecoregion-already subjected to increased human development and climate change. Of n = 2019 vertebrates observed, 28.5% were roadkill. Increasing urbanization levels were associated with reduced vertebrate abundance on roads and increased road-killed endothermic vertebrates. Traffic volume was strongly associated with reduced vertebrate abundance and increased roadkill; additive effects on roadkill began at approximately 20 vehicles. Daily low temperature and/or relative humidity were also associated with roadkill across vertebrate groups. We provide empirical evidence to understand wildlife-roadkill associations across expanding wildland-urban interfaces to inform effective roadkill mitigation and wildlife conservation management strategies in biodiverse aridland regions. We recommend that managers mitigate or avoid development in rural areas that possess high biodiversity, valuable waterways or migration corridors, and populations of vulnerable species.

Road mortality rate of the butterflies at National Highway in Cuddalore District, Tamil Nadu, India

Road mortality rate of the butterflies at National Highway in Cuddalore District, Tamil Nadu, India

Modeling of Car-to-motorcycle Overtaking Maneuver Based on Comfort Zone Boundaries

Thailand has one of the world's highest road fatality rates, mainly on motorcycles. In mixed traffic, motorcycles coexist with other vehicles. The interaction between cars and motorcycles, such as overtaking due to speed differences, can lead to accidents. This scenario also has implications for autonomous vehicles interacting with motorcycles. To increase safety in such interactions, a model was developed that simulates overtaking maneuvers of car drivers with motorcycles, using the concept of comfort zone boundary and a four-phase classification. In a driving simulator, 648 overtaking maneuvers collected from 36 Thai drivers were recorded with different lateral positions and speeds of the motorcycles. A novel graphical method using steering wheel angle and steering wheel velocity signals facilitated the identification of the phases. Time-to-collision and lateral distance characterized driver comfort zones and served as an indicator for safety measures. The lateral position of the motorcycle has proven to be the most influential factor in the model. The results suggest that overtaking vehicles exhibit non-lane-bound driving characteristics and a risk for the sideswipe accident is identified. These results provide a foundational framework for advanced driver assistance systems and motion planning of autonomous vehicles, contributing to improved road safety.

Understanding habitat suitability and road mortality for the conservation of the striped hyaena (Hyaena hyaena) in Batna (East Algeria)

Abstract The determination of suitable habitats and roadkill hotspots allows for the prioritization of areas of conservation and the identification of road sections that require appropriate planning and development. Understanding the factors that influence the species’ presence and those contributing to its road-related fatalities is crucial. This study demonstrates the use of MaxEnt modeling to map the potential distribution of the striped hyaena (Hyaena hyaena) in Batna province (East Algeria) using occurrence records and a set of environmental variables. The results indicated that the two primary environmental variables that influence the distribution of the species are the shrubland, and the slope with a contribution of 37.5 and 30.2 %, respectively, followed by built-up areas (12 %) and distance to roads (7.2 %). The species may occupy steep terrain with shrubland near anthropized areas. Road collisions represent a threat to the species, with 28 documented casualties from 2010 to 2020 in Batna. The kernel density estimation revealed an important roadkill hotspot along the national roads 3 and 28. This study represents a preliminary step for the use of wildlife ecological niche modeling and road management in Algeria.

Reptiles in danger: Implications of road mortality in wetlands of South America

Abstract Undoubtedly, roads produce negative effects on wildlife, but when they are laid across wetlands effects can be exacerbated. The “hyperfragmentation” and loss of terrestrial and aquatic habitats generated by roads makes it urgent to measure effect on wildlife. Reptiles are highly susceptible to road mortality mainly because of their slow movement, and the use of roads as a substrate for thermoregulation and feeding areas. Here, we analysed reptile road mortality in the floodplain of the Paraná River (Argentina) at three sections: North (NS), Centre (CS), and South (SS). We compared the richness and abundance of reptile roadkill species that use different habitats by means of monthly samplings. We found 464 roadkills encompassing 27 species (1 turtle, 2 lizards, and 24 snakes). Despite a greater richness of terrestrial species, roadkill abundance was always dominated by aquatic species. We detected two hot spots of reptile roadkill where routes cross the Paraná River floodplain and the environment quality was high: one in the NS, located in a protected area with records of two Vulnerable species; and another hot spot in the SS, which recorded roadkills that belonged to almost all inhabiting snake species and presented the highest roadkill abundance. A temporal ‘hot moment’ of reptile roadkill occurrence was detected during autumn in the SS. This study provides a baseline for delineating measures to prevent and mitigate reptile mortality, focusing on specific places, moments, and taxa in roads crossing wetlands in the Paraná River floodplain.

The impact of urbanization on painted turtle (Chrysemys picta) behaviour

AbstractUrbanization is a significant driver of the global biodiversity crisis. Turtles are particularly impacted by urbanization because of the vulnerability of riparian habitats to habitat loss and road mortality. Behaviour plays a crucial role in determining the success of urban animals. Behavioural responses to urbanization, however, are rarely studied in turtles even though many turtles are at‐risk and sometimes live in urban areas. Therefore, we evaluated behavioural changes in painted turtles (Chrysemys picta) living in wetlands surrounded by a gradient of urbanization. We tested the consistency of painted turtle behaviour in the laboratory and examined the behaviour of painted turtles from 24 wetland sites across an urbanization gradient in Ottawa, Ontario, Canada. We assessed: (i) aggression by measuring the number of active defensive behaviours the turtles performed in response to handling, (ii) boldness by measuring the amount of time the turtles took to emerge from their shells and move from their initial locations in a circular arena and (iii) activity by measuring the amount of time the turtles spent moving in the same circular arena. We found that all behaviours were consistent in the laboratory. We also found that as the level of urbanization increased, turtles were more aggressive and bolder. Urbanization affects painted turtle behaviour, but further research is required to understand the mechanisms responsible and the conservation implications.

Using the dead to infer about the living: Amphibian roadkill spatiotemporal dynamics suggest local populations' reduction

Roads represent one of the main sources of wildlife mortality, population decline, and isolation, especially for low-vagility animal groups. It is still not clearly understood how wildlife populations respond to these negative effects over space and time. Most studies on wildlife road mortality do not consider the spatial and temporal components simultaneously, or the imperfect roadkill detection, both of which could lead to inaccurate assumptions and unreliable mitigation actions. In this study, we applied a multi-season occupancy model to a 14-year amphibian mortality dataset collected along 120 km of roads, combined with freely available landscape and remote sensing metrics, to identify the spatiotemporal patterns of amphibian roadkill in a Mediterranean landscape in Southern Portugal. Our models showed an explicit general decrease in amphibian roadkill. The Iberian painted frog (Discoglossus galganoi) experienced roadkill declines over time of ∼70 %, while the spiny common toad (Bufo spinosus) and the fire salamander (Salamandra salamandra) had a loss of nearly 50 %, and the Southern marbled newt (Triturus pygmaeus) had 40 %. Despite the decreasing trend in roadkill, spatial patterns seem to be rather stable from year to year.Multi-season occupancy models, when combined with relevant landscape and remote sensing predictors, as well as long-term monitoring data, can describe dynamic changes in roadkill over space and time. These patterns are valuable tools for understanding roadkill patterns and drivers in Mediterranean landscapes, enabling the differentiation of road sections with varying roadkill over time. Ultimately, this information may contribute to the development of effective conservation measures.

Rabies can lead to carnivores-vehicle collisions: A survey in Fars province, Iran

Road mortality caused by collisions with vehicles is the most tangible impact of road networks on wildlife. Neurological disorders in animals resulting from infectious diseases such as rabies can exacerbate the risk of road kills. To investigate this aspect, we examined 10 carnivores that had collided with cars and were subsequently transferred to the Bamou Rescue Centre. The Fluorescent Antibody Test (FAT) results were positive for rabies in four individuals. In addition to these four carnivores involved in vehicle collisions and found to be rabid, three other wild individuals in the province were reported to be infected with rabies without any history of road accidents. Rabies thus poses a significant threat to wildlife biologists, public health officials, and veterinarians who are typically involved in rescuing carnivores involved in road accidents. These findings emphasize the importance of veterinarians being knowledgeable about the potential causes and backgrounds of carnivore road accidents.

A comparison of traditional road safety assessment methods and the newly developed 'road safety deserts' approach

Road fatalities were labelled a pandemic as early as 1973 (BMJ 1973). The number of road fatalities reached 1.35 million in 2016. Currently over 3 500 people perish every day on the world's roads. South Africa has one of the highest road fatality rates in the world, with a fatality rate of 25.9 deaths per 100 000 population (WHO 2018). In order to understand and improve the road safety situation of a region, effective road safety assessments must be carried out. This paper presents a comparison of four different road safety assessment approaches, both traditional and novel, and serves as a proof of concept for the 'road safety desert' methodology, a new technique adapted from the 'transit desert' concept. This new approach to road safety assessment explores the possibility of geo-coded supply and demand comparisons to identify 'road safety deserts' - areas that have a comparatively higher road safety risk. This paper shows that there are several unique and effective ways to assess road safety, and that each approach incorporates different characteristics within their methodologies. It is recommended that road safety analysis is conducted using a multitude of methods, so as to improve understanding and intervention selection.

Beyond crippling bias: Carcass‐location bias in roadkill studies

AbstractWildlife roadkill studies need to cope with a mismatch among recorded carcasses and actual road mortality, because of the existence of three biases: crippling, carcass‐persistence, and observer bias. Here, we focused on the often overlooked crippling bias, suggesting that it should be called carcass‐location bias and disentangling the related three possible outcomes for affected wildlife: injured animal escaping and dying away from road, animal rebounding off the road after vehicle collision, and animal retained by vehicle. Such outcomes can probably be affected by different species traits, and, in order to make a first evaluation of this hypothesis, we opportunistically collected 150 direct observations on the ultimate fate of roadkilled vertebrates. Approximately one third of them were affected by carcass‐location bias, so extremely difficult to be recorded through typical roadkill surveys, entailing a considerable and overlooked source of error for roadkill studies and mitigation actions based on them.

Assessing habitat connectivity of rare species to inform urban conservation planning.

Urbanization is commonly associated with biodiversity loss and habitat fragmentation. However, urban environments often have greenspaces that can support wildlife populations, including rare species. The challenge for conservation planners working in these systems is identifying priority habitats and corridors for protection before they are lost. In a rapidly changing urban environment, this requires prompt decisions informed by accurate spatial information. Here, we combine several approaches to map habitat and assess connectivity for a diverse set of rare species in seven urban study areas across southern Michigan, USA. We incorporated multiple connectivity tools for a comprehensive appraisal of species-habitat patterns across these urban landscapes. We observed distinct differences in connectivity by taxonomic group and site. The three turtle species (Blanding's, Eastern Box, and Spotted) consistently had more habitat predicted to be suitable per site than other evaluated species. This is promising for this at-risk taxonomic group and allows conservation efforts to focus on mitigating threats such as road mortality. Grassland and prairie-associated species (American Bumble Bee, Black and Gold Bumble Bee, and Henslow's Sparrow) had the least amount of habitat on a site-by-site basis. Kalamazoo and the northern Detroit sites had the highest levels of multi-species connectivity across the entire study area based on the least cost paths. These connectivity results have direct applications in urban planning. Kalamazoo, one of the focal urban regions, has implemented a Natural Features Protection (NFP) plan to bolster natural area protections within the city. We compared our connectivity results to the NFP area and show where this plan will have an immediate positive impact and additional areas for potential consideration in future expansions of the protection network. Our results show that conservation opportunities exist within each of the assessed urban areas for maintaining rare species, a key benefit of this multi-species and multi-site approach.

Spatiotemporal Patterns of Reptile and Amphibian Road Fatalities in a Natura 2000 Area: A 12-Year Monitoring of the Lake Karla Mediterranean Wetland.

The pervasive expansion of human-engineered infrastructure, particularly roads, has fundamentally reshaped landscapes, profoundly affecting wildlife interactions. Wildlife-vehicle collisions, a common consequence of this intricate interplay, frequently result in fatalities, extending their detrimental impact within Protected Areas (PAs). Among the faunal groups most susceptible to road mortality, reptiles and amphibians stand at the forefront, highlighting the urgent need for global comprehensive mitigation strategies. In Greece, where road infrastructure expansion has encroached upon a significant portion of the nation's PAs, the plight of these road-vulnerable species demands immediate attention. To address this critical issue, we present a multifaceted and holistic approach to investigating and assessing the complex phenomenon of herpetofauna road mortality within the unique ecological context of the Lake Karla plain, a rehabilitated wetland complex within a PA. To unravel the intricacies of herpetofauna road mortality in the Lake Karla plain, we conducted a comprehensive 12-year investigation from 2008 to 2019. Employing a combination of statistical modeling and spatial analysis techniques, we aimed to identify the species most susceptible to these encounters, their temporal and seasonal variations, and the ecological determinants of their roadkill patterns. We documented a total of 340 roadkill incidents involving 14 herpetofauna species in the Lake Karla's plain, with reptiles, particularly snakes, being more susceptible, accounting for over 60% of roadkill occurrences. Moreover, we found that environmental and road-related factors play a crucial role in influencing roadkill incidents, while spatial analysis techniques, including Kernel Density Estimation, the Getis-Ord Gi*, and the Kernel Density Estimation plus methods revealed critical areas, particularly in the south-eastern region of Lake Karla's plain, offering guidance for targeted interventions to address both individual and collective risks associated with roadkill incidents.