Daylight saving time will end in the US and Canada on November 7, 2021, and most of us will be setting our clocks back an hour. The benefit of timing change has long been debated, given how it disrupts humans’ circadian rhythms, leading to short-term stress and fatigue.
Another risk is on the roads as times change: as more people drive in the evening during deer-active times, the number of deer-vehicle accidents increases.
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 reveal about timing and exposure.
Time of day, month and year matters
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 more than four times as many deer-vehicle accidents during the spring as during that period. Moose-vehicle accidents show a similar pattern.
daylight saving time problem
We have also found that a one-hour daylight saving time clock shift affects the number of deer-vehicle accidents.
In the spring, when deer-vehicle accidents are less frequent annually, the introduction of daylight saving time means a later sunrise and sunset. This leads to a slight reduction in deer-vehicle accidents. However, in the fall, when deer-vehicle accidents caused by deer are at an annual high, earlier sunrises and sunsets cause a significant increase in deer-vehicle accidents.
The clock shift results in more commuters on the road during the high-risk evening hours. The result is more cars driving during peak times of the day and peak times of the year for deer-vehicle accidents. Clock shifts cause a 37% reduction in deer-vehicle accidents during the morning commuter hours because fewer passengers are on the road before sunrise, but a 72% increase in accidents during the evening commuter hours. Overall, there is a 19% increase in accidents during commuter hours a week after the change in fall timings in New York.
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 hitting 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. In addition, drivers should be aware that as fall times change, they may become more tired, and their evening commute from work may shift into the evening hours, when the risk of hitting a deer is highest. , and coincides with the rut, when risk is at its annual peak.
This is an update of an article previously published on September 21, 2021.
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