Autumn is here, and that means there is an increasing risk of deer hitting rural roads and highways, especially around dusk and during the full moon.
Deer cause more than 1 million motor vehicle accidents in the US each year, resulting in more than US$1 billion in property damage, nearly 200 human deaths and 29,000 serious injuries. Property damage insurance claims average about $2,600 per accident, and the total average cost, including serious injuries or death, is more than $6,000.
If you are driving in rural areas, it may seem impossible to avoid deer as well as moose, elk, and other hoofed animals, but certain times and places are most dangerous, and therefore require extra precautions. .
Transportation agencies, working with scientists, are developing ways to predict where deer and other ungulates enter roads so that they can post warning signs or fences or wildlife walkways along or above the road. be able to install. Equally important is knowing when these accidents happen.
My former students Victor Colino-Rabanal, Nimanthi Aberthna, and I have analyzed more than 86,000 deer-vehicle collisions involving white-tailed deer in New York State using police records over a three-year period. Here’s what our research and other studies say about timing and exposure:
Time of day, month and year matter
The risk of killing a deer varies by time of day, day of the week, monthly lunar cycle, and season of the year.
These crash cycles are partly a function of driver behavior – when traffic is heavy, drivers are least alert and driving conditions are at their worst to see animals. They are also influenced by the behavior of the deer. More often than not, deer-vehicle accidents involve multiple vehicles, as startled drivers tend to miss a deer and collide with a vehicle in the other lane, or they slam on the brakes and are followed by the vehicle behind. ends towards.
In analyzing thousands of deer-vehicle collisions, we found that these accidents occur most frequently at dusk and dawn, when deer are most active and drivers’ abilities to detect them are at their worst. Only 20% of accidents occur during daylight hours. Deer-vehicle accidents occur eight times more often per hour than during daylight hours, and four times more frequently in the evening than after nightfall.
During the week, accidents occur most frequently on days that have the most drivers on the road during dawn or dusk, so they are linked to commuter driving patterns of work and social factors such as Friday “date night” traffic. .
Over a one-month period, most deer-vehicle accidents occur during the full moon, and during the night when the moon is at its brightest. Deer cover greater distances and are more likely to enter roadways when there is more light at night. The pattern holds for deer and other ungulates in both North America and Europe.
In a year, the greatest number of deer-vehicle accidents occur in autumn, and especially during the rut, when bucks hunt and compete to mate. In New York State, the peak number of deer-vehicle accidents occurs in the last week of October and the first week of November. There are four times more deer-vehicle accidents during that period than during the spring. Moose-vehicle accidents show a similar pattern.
That high-risk period is also when daylight saving time ends – it happens on November 7, 2021, shifting the clock an hour earlier in the US means more commuters on the road during the high-risk evening hours are on. The result is more cars driving during peak times of the day and peak times of the year for deer-vehicle accidents.
Overall, given that most US states and more than 70 countries have seasonal “daylight saving” clock shifts, the uncontrolled-vehicle accident rates caused by clock shifts can be a widespread problem.
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The benefits of daylight saving clock shifts have long been debated, given how it disrupts humans’ circadian rhythms, causing short-term stress and fatigue. The risk of deer-vehicle accidents may be another reason to reconsider whether clock shifts are worthwhile.
deer still cross the road at any time
It’s important to remember that deer-vehicle accidents can happen at any time of day or night, any day of the year – and that deer can appear in urban areas as well as rural areas.
Insurance company State Farm found that, on average, American drivers have a 1 in 116 chance of killing an animal, with much higher rates in states such as West Virginia, Montana, and Pennsylvania. In the 12 months ending June 2020, State Farm counted 1.9 million insurance claims for collisions with wildlife nationwide. About 90% of them consisted of deer.
Where deer or other ungulates are likely to be present, drivers should always be alert and alert, especially at dawn, dusk, on bright moonlit nights and during the fall.