Road Traffic Mortality in Wildlife: Scale and Mitigation

Roads kill billions of animals annually worldwide. Understanding the scale of this welfare problem and available mitigation measures helps reduce wildlife suffering from traffic.

Key Facts

Roads kill an estimated 1-2 million vertebrate animals per day in the US alone
Amphibians, reptiles, and small mammals face the highest per-individual road mortality rates
Badger, hedgehog, and red squirrel populations in the UK are significantly impacted by road mortality
Culverts and tunnels under roads allow small mammal and amphibian movement with good results
Wildlife cameras confirm use of crossing structures by diverse species including large predators
Road mortality removes individuals in their prime reproductive years, disproportionately impacting populations
Seasonal migration routes concentrate road mortality in time and space, creating high-risk periods for specific species

Welfare Considerations

Road traffic mortality causes traumatic death and injury to billions of animals annually. Animals struck by vehicles may die immediately or experience prolonged suffering from injuries before succumbing. The predictable concentration of mortality at crossing points means the welfare harm is avoidable through targeted infrastructure solutions. Beyond mortality, road avoidance behavior restricts animal movement, reducing access to resources and mates. The cumulative welfare harm of roads - through direct mortality and population fragmentation - is one of the most significant human-caused animal welfare problems and one of the most tractable through engineering solutions.

What You Can Do

Reduce vehicle speed in known wildlife crossing areas especially at dawn, dusk, and during migration seasons
Avoid driving at high speed through wildlife-rich areas at night when visibility is reduced
Support transportation departments in installing crossing structures in wildlife movement corridors
Report road casualty sightings to wildlife organizations that track mortality hotspots
Advocate for wildlife crossing requirements in new road construction and significant road upgrades
Participate in community science programs that document road mortality to identify priority mitigation sites
Support hedgehog highways and garden connectivity in urban areas to reduce road mortality for small mammals