Wildlife Road Mortality: Scale, Welfare, and Practical Mitigation

Road vehicle collisions kill billions of wild animals annually worldwide, representing one of the most significant human-caused welfare impacts on wildlife. Effective mitigation exists and is increasingly implemented.

Key Facts

Roads kill an estimated 1 million vertebrates per hour in the United States alone
Badgers, hedgehogs, barn owls, deer, and otters are among the most severely affected UK species
Wildlife crossing structures including underpasses, overpasses, and culverts with appropriate fencing reduce mortality by 70-90%
Reflective roadside devices and wildlife warning signs have variable and generally limited effectiveness compared to physical barriers
Seasonal speed reductions in key wildlife movement areas reduce peak-period mortality for migrating species
Road ecology as a discipline provides evidence-based guidance for new road design that minimizes habitat fragmentation and mortality
Urban wildlife mortality from traffic is disproportionately overlooked relative to rural road mortality in most studies

Welfare Considerations

Road mortality welfare is a massive but largely invisible welfare emergency: billions of animals die annually on roads worldwide, each death involving acute trauma and often prolonged suffering from non-fatal injury. The scale makes this one of the most significant human-caused welfare harms to wildlife globally. The frustrating aspect is that effective solutions are known: wildlife crossing structures with appropriate fencing have been demonstrated to reduce wildlife-vehicle collisions by 70-90% in multiple studies in multiple countries. The barrier to implementation is economic rather than technical - crossing structures are expensive to retrofit to existing roads. New road construction presents an opportunity to incorporate crossing structures from the design stage, and advocacy for this in road planning processes is one of the most impactful wildlife welfare interventions available.

What You Can Do

Advocate for wildlife crossing structures to be included in new road construction and major road widening projects
Support wildlife-friendly road design in local planning processes by engaging with environmental impact assessments
Drive carefully in areas with wildlife warning signs and reduce speed at dawn and dusk when wildlife is most active
Support wildlife charities that advocate for road ecology improvements and wildlife crossing infrastructure
Report wildlife road casualties to citizen science programs that map mortality hotspots to inform mitigation priorities