Daylight Saving Time Change Brings Far Greater Odds of Hitting a Deer — Here's Why

The risk of a deer-vehicle collision is 14 times higher in the two hours after sunset than in the two hours before sunset, due to the dramatic reduction in driver visibility in darkness.

The Hidden Danger of Turning Back the Clock

When clocks fall back one hour each November, most Vermonters think about gaining an extra hour of sleep. But research shows this annual time change creates a sharp and dangerous spike in deer-vehicle collisions — a 16% nationwide increase in the week immediately following the shift to Standard Time, according to a 2022 study published in Current Biology.

The timing couldn’t be worse for Vermont drivers. The state ranks 21st in the nation for animal-vehicle collision risk, with motorists facing 1 in 108 odds of such a crash, according to State Farm’s 2024-2025 data. That’s notably higher than neighboring New Hampshire (1 in 189) and New York (1 in 167).

Why the Time Change Is So Dangerous

The problem stems from a fundamental mismatch between human schedules and animal behavior. While people organize their lives around clock time, deer activity is governed by natural light cycles — specifically sunrise and sunset.

The Current Biology study by researchers Calum Cunningham and colleagues analyzed over one million deer-vehicle collisions across 23 states and identified a critical pattern: deer are crepuscular animals, meaning they’re most active at dawn and dusk. More importantly, the risk of a collision is 14 times higher in the two hours after sunset than in the two hours before sunset, primarily due to darkness reducing driver visibility.

When clocks “fall back” in early November, the evening commute that previously occurred during twilight suddenly takes place in full darkness. This abrupt one-hour shift creates a massive overlap between rush hour traffic and the high-risk period when deer are most active and visibility is lowest.

Vermont’s Unique Vulnerability

While the study didn’t provide Vermont-specific data, several factors suggest the state is particularly vulnerable to this phenomenon:

Timing with mating season: The early November time change coincides precisely with the white-tailed deer rut (mating season), which typically runs from October through mid-December in the Northeast. During this period, deer are significantly more active, cover more territory, and exhibit less caution when crossing roadways, according to the Vermont Fish & Wildlife Department.

East Coast effect: The study’s authors specifically noted that the collision spike was more pronounced on the East Coast, attributed to higher deer densities in eastern states compared to many western regions.

Rural road network: Vermont’s landscape is characterized by rural, two-lane roads that cut through extensive forest habitat. The state has approximately 140,000 deer and only 625,664 registered vehicles, according to Vermont Fish & Wildlife estimates and Federal Highway Administration data. This translates to just 4.5 vehicles per deer — far lower than New Hampshire’s 14.4 vehicles per deer or New York’s 12.0 vehicles per deer.

This counter-intuitive finding suggests Vermont’s higher collision risk isn’t about having more deer or more cars, but rather about how frequently their paths cross on roads that bisect prime habitat.

The National Picture

Nationally, deer-vehicle collisions represent a significant public safety and economic problem. According to data compiled by State Farm and cited by the Pew Charitable Trusts, an estimated 1 to 2 million crashes involve large animals annually, resulting in approximately 200 human fatalities, 26,000 injuries, and at least $8 billion in costs.

The Insurance Institute for Highway Safety reports that 77% of fatal animal crashes involve deer. October through December account for 41% of all annual animal collision claims — roughly 650,000 incidents during those three months alone.

High-Risk Locations in Vermont

Certain roads and landscape features create particularly dangerous conditions for deer encounters:

Identified high-risk routes include U.S. Route 7 (running through the Green Mountain National Forest), U.S. Route 2 (following the Winooski River valley), Vermont Route 9 (Molly Stark Byway), and Vermont Route 15 across northern Vermont, according to transportation safety analyses.

Dangerous landscape features include areas where forests meet open fields, roads near streams and wetlands, and corridors cutting through connected forest blocks. The Vermont Agency of Natural Resources notes these “edge” environments are prime deer habitat.

According to AAA Northern New England data from 2019, 32% of all deer-related crashes in Vermont occurred in just November and December.

How Drivers Can Reduce Risk

Transportation safety experts recommend several defensive driving techniques:

Be vigilant during high-risk times: Dawn and dusk are the most dangerous periods. Exercise extreme caution during evening commutes in November, when the time change effect is strongest.

Scan actively: Look beyond the road surface to shoulders and ditches. At night, watch for eye shine — the reflection of headlights in animals’ eyes.

Remember the “one deer” rule: Deer travel in groups. If one crosses, slow down immediately and expect others to follow.

Use high beams: When there’s no oncoming traffic, high beams illuminate more of the roadside where deer may be waiting to cross.

Brake, don’t swerve: This is the most critical advice. Many serious injuries occur not from hitting the deer, but from swerving into oncoming traffic, trees, or other objects. Brake firmly and stay in your lane.

What to Do After a Collision

If you hit a deer in Vermont:

1. Move to safety and turn on hazard lights

2. Call 911 or local police, especially if there are injuries or the vehicle is disabled

3. Under Vermont law (23 V.S.A. § 1129), file a written report with the Commissioner of Motor Vehicles within 72 hours if there are injuries or property damage exceeds $3,000

4. Document the scene with photos if safe to do so

5. Do not approach the animal — wounded deer can be dangerous

6. Contact your insurance company. Animal collisions are typically covered under comprehensive coverage, not collision coverage

7. Under Vermont statute (10 V.S.A. § 4749), you may claim the carcass if an official issues a tag number, allowing the venison to be utilized

The Policy Debate

The Current Biology study modeled potential policy changes to address this problem:

Permanent Daylight Saving Time (keeping clocks “forward” year-round) would prevent an estimated 36,550 deer deaths, 33 human deaths, and 2,054 human injuries annually, saving $1.19 billion in collision costs nationwide.

Permanent Standard Time would have the opposite effect, the study found, increasing collisions and resulting in an additional 73,660 crashes, 66 human deaths, and $2.39 billion in costs annually.

The research demonstrates that a societal convention seemingly unrelated to transportation has direct, measurable impacts on road safety.

What Happens Next

Vermont continues to observe the biannual time change, meaning drivers will face this elevated risk each November for the foreseeable future. The next “fall back” transition will occur on November 2, 2025, at 2:00 a.m.

The Vermont Agency of Transportation maintains a Public Crash Data Query Tool that could be used to analyze Vermont-specific patterns around the time change, though no state-level study has been published to date.

For Vermont drivers, awareness remains the primary defense. Understanding that the first week of November combines three risk factors — the time change, the peak of deer mating season, and darkened evening commutes — can help motorists adjust their driving behavior during this particularly dangerous period.

The phenomenon illustrates how human systems and natural rhythms intersect in unexpected ways, creating risks that can be anticipated and, with proper caution, mitigated.