Daylight Saving Time Increase Deer-Vehicle Collisions, Wildlife Experts Warn
On November 2, 2025, the U.S. and Canada will end daylight saving time by setting clocks back an hour, a change linked to rising deer-related traffic accidents. Beyond human circadian disruptions, this shift intensifies risks on roadways, coinciding with peak periods of deer activity.
Each year, deer cause over one million vehicle collisions in the United States, resulting in more than $1 billion in property damage, approximately 200 fatalities, and 29,000 severe injuries. Insurance claims average around $2,600 per incident, with total costs—including serious injuries and deaths—exceeding $6,000 per accident.
Timing and Location Influence Collision Risk
According to research analyzing over 86,000 white-tailed deer collisions in New York state from police records over three years, the risk of hitting a deer strongly depends on the time of day, season, and lunar cycle.
Deer-vehicle crashes peak at dawn and dusk, aligning with crepuscular behavior typical of white-tailed deer and many other ungulates. These twilight hours coincide with reduced visibility for drivers, making it difficult to detect fast-moving animals near roadways. Collisions are eight times more frequent at dusk compared to daylight and four times more likely at dusk than during full darkness.
Additionally, collisions tend to occur on days with higher traffic volume during these vulnerable times, often leading to multi-vehicle accidents when drivers swerve or brake suddenly to avoid deer.
Wildlife Behavior and Driver Awareness Are Key
Deer movement patterns in late autumn contribute to elevated accident rates, as this period includes the rutting season when males increase activity and may cross roads unpredictably. Earlier dusk caused by the end of daylight saving time places more drivers on roads during periods of high deer movement.
Transportation agencies collaborate with ecologists to identify high-risk zones where deer frequently cross roads. Measures such as fencing, wildlife overpasses, and targeted signage are increasingly used to mitigate these encounters.
Expert Insight
Tom Langen, a wildlife expert at Clarkson University, emphasizes the importance of understanding both animal behavior and driver patterns to reduce collisions. He notes that integrating ecological data with transportation planning is essential to protect both humans and wildlife.
Practical Advice for Motorists
- Exercise extra caution during dawn and dusk, especially in rural or forested areas known for deer presence.
- Be alert in early November and other peak deer movement seasons.
- Adhere to posted wildlife crossing signs and reduce speeds where recommended.
- Understand that deer often travel in groups, so one crossing animal may indicate others nearby.
As daylight saving time ends on November 2, 2025, drivers should prepare for increased deer activity on the roads to help reduce accidents and protect both human and wildlife lives.
Additional reporting and sources from: Another problem with daylight saving time: The time change raises your risk of hitting deer on the road
