Designing crossing structures for wildlife underneath roads is a challenge because species may respond differently to factors such as nearby habitat or crossing-structure dimensions. Here we show that large, open crossing structures along natural travel corridors accommodate the highest diversity of large and medium-sized mammals.

We identified key areas and species that should be prioritized for conservation and research related to road impacts. In Latin America, vultures, armadillos, cuckoos and shrew opossums need protection, and Central America and northern South America are the regions with the greatest need for research.

Nearly 9 million medium- and large-sized mammals (>1kg) could be killed on Brazilian roads each year, representing an estimated wildlife biomass of over 10,000 tons. Mortality from roads is a major threat to wildlife conservation in Brazil, and further research and mitigation is urgently needed to avoid species extinction.

The tiny Leadbeater’s possum is critically endangered from a combination of habitat destruction, timber harvesting, the effects of high-intensity forest fires, and habitat fragmentation from roads and fire-breaks. We tested two different designs of canopy bridges across roads in their forest habitat and both were used, reducing the risk of predation by terrestrial predators and wildlife-vehicle collision.

Our recent survey of the transport planning and policy literature revealed substantial barriers that obstruct the consideration and implementation of fauna-sensitive road design (FSRD). Although the review identified several ecological support tools that could be useful to transport practitioners, these are of limited use without ‘action-oriented’ research to support their adoption and application of FSRD more broadly.

Mammal roadkill can negatively affect wildlife populations but exactly how it does so remains unclear. This study reviewed globally published studies to examine how roadkill affects populations.

We present a simple framework for a landscape level approach to identify species road crossing needs and priority sites for implementation. Our approach permits pro-active, scenario-based planning for wildlife friendlier roads that can easily be incorporated into EIAs.

Managing road verges to promote flowers has been proposed as a conservation tool for pollinating insects in many parts of the world but there is a concern that these habitats might be attracting the insects to a highly deadly environment. We investigated whether traffic mortality of bumblebee queens was impacted by the flowering plant diversity in the road verge and the traffic volume and found that the probability of observing dead queens quadrupled when traffic increased from 100 to 6000 vehicles per day.

A dramatic global rise in wildlife mortality due to vehicle collision has boosted a wide interest across disciplines to mitigate this impact through the installation of structures such as overpasses, underpasses, fences, etc. These structures can restore connectivity and improve population viability, even though research has found that some structures need to increase their effectiveness. So, it is more important than ever for optimal planning initiatives to be more precise, resilient, and adaptable enough to work for a wide range of species and taxa.

The opposite effects of roads (barriers) and road verges (corridors) have been not studied simultaneously and it is therefore unknown what the overall effect of road infrastructure is on the populations of pollinating insects. We used an experimental approach that allowed us to simulate pollen transfer between flowers placed in road verges with different flower densities to track the movement of flower-visiting insects in road environments.

Apex predators play critical roles in maintaining ecosystem health, but our meta-analysis on 36 species from around the world found all are affected by roads, and particularly in Asia. Proposed road projects in the Brazilian Amazon, Africa and Nepal will affect roughly 500 protected areas and threaten what little remains of apex predator’s core habitats, driving many species closer to extinction. Better planning to avoid such areas is urgently needed.

Our recent survey of the literature revealed a need for significant improvement in how road ecology studies should be designed and conducted if we are to achieve real-world impact beyond the research. We developed a framework that aims to assist road ecologists and transport practitioners in conducting research that will make meaningful contributions to the evolution of the field and have real-world applications.

Environmental Impact Assessments (EIA) for planned road projects usually neglect landscape-scale effects. We discuss 14 necessary steps to better assess ecological connectivity in EIA and reduce its degradation and/or loss.

By mapping road- and railroad-less areas in Brazil we identified priority areas for conservation and restoration. Our study also demonstrated that there is less native vegetation near roads and railroads compared to further away.

Underpasses are a useful tool to enable wildlife to move across landscapes with roads. Not all ground-dwelling species of wildlife will find underpasses to their liking, but many do. Underpasses are also not a panacea for impacts on wildlife. And we shouldn’t use their effectiveness as a justification to run highways through pristine areas. They’re a tool to minimise impacts of road projects that have wide community support.

A review of 1517 studies from around the world concludes that population-level studies are highly underrepresented and addressed road impacts on only 2% of threatened species. Most research was in developed nations, while developing countries are lagging behind.

We used a long-term citizen science data set of bat roadkill and found the rates of mortality were higher in protected areas than non-protected area at higher elevation in Taiwan. In contrast, roadkill of common bat species was best explained by high levels of light pollution at lower elevations, suggesting that bats might be exposed to higher collision risk when they were attracted by insects around streetlights.

We searched Chinese and international databases for peer-reviewed papers on road ecology in China and found 170 papers. Our review of those focussed on identifying ecological impacts, research themes, knowledge gaps, and future research directions. The transport network in China is one of the largest in the world, and our review will guide our work in China and abroad.

Short stretches of fences can substantially reduce roadkill along a fenced road section, especially if fence-end treatments are in place. However, with short fences there may still not be a net benefit because roadkill can be moved to nearby unmitigated road sections, especially just beyond a fence-end

Wolves are recolonizing many parts of central Europe, which often requires them to cross roads to reach new habitats and territories. We found that green bridges (also known as land bridges) are used by wolves and by their prey, and reduce the risk that wolves are involved in wildlife-vehicle collisions.