Wildlife Road Mortality and Mitigation Infrastructure

Roads kill billions of animals globally each year through collision, habitat fragmentation, and barrier effects, with wildlife crossing infrastructure significantly reducing mortality and improving population connectivity.

Key Facts

Estimates suggest that over a million vertebrate animals are killed on roads globally every day
Wildlife crossings including underpasses, overpasses, and culverts with appropriate fencing can reduce road mortality by over 90% for target species
Banff National Park in Canada has demonstrated that large mammal crossings are effective for bears, wolves, elk, and cougars over decades
Amphibians are particularly vulnerable — seasonal migrations to breeding ponds cross roads en masse, with entire local populations at risk from single road segments
Roadkill monitoring volunteer networks in many countries are generating data that identifies priority locations for mitigation measures
Vegetation planted on wildlife crossings increases their attractiveness to wide-ranging mammals that are slow to accept novel structures
Light and noise from roads cause welfare harms beyond direct collision mortality, including foraging disruption, predation pressure changes, and reproductive stress

Welfare Considerations

Road mortality is one of the largest direct human causes of wildlife death globally, yet it remains largely invisible because individual deaths are dispersed across thousands of kilometres of road. The welfare harms extend beyond collision death to include the ongoing stress of road noise and light, habitat fragmentation that reduces access to food and mates, and the genetic isolation that follows population fragmentation. Wildlife crossing infrastructure is proven to work but requires sustained political will and capital investment. Citizen science roadkill monitoring that identifies blackspots has proven effective in generating the evidence base needed to justify mitigation investment. Individual drivers can reduce their impact through speed reduction in wildlife-active areas and wildlife-friendly driving at night.

What You Can Do

Reduce speed and drive vigilantly in areas with known wildlife road mortality hotspots
Support citizen science roadkill monitoring schemes in your country
Advocate for wildlife crossing infrastructure in major road planning and upgrade projects
Engage your local highway authority about wildlife casualty data and priority mitigation sites
Donate to organisations campaigning for amphibian crossing tunnels on roads near breeding ponds
Support planning policy requirements for wildlife connectivity assessment in road development
Participate in or fund amphibian bucket brigade volunteer operations during spring migrations