It’s November. Stay vigilant.

As the temperature drops and the days grow short, vehicle-deer collisions increase. It’s a yearly cycle driven by biology, infrastructure, hunting and the time change.

The primary driver of increased deer-vehicle collisions is the fact that deer are heading into mating season — known as the rut. This sends sex-focused male deer dashing across highways and roads.

“The bucks are just not paying attention to anything,” said Sara Hansen, a deer specialist for the Washington Department of Fish and Wildlife.

However, the secondary reasons for the increased collisions are human related. First, the end of daylight saving time suddenly changes when humans are driving.

“The animals don’t know that changing traffic pattern is coming,” Hansen said. “And then all of a sudden the humans have changed by an entire hour.”

Also, hunters push deer toward a more nocturnal schedule, sending the ungulates crossing roads more frequently at night.


“They’re pretty smart,” she said.

All that leads to a potentially disastrous mix. According to an analysis by State Farm, one out of every 258 Washington drivers hit a deer, moose or elk in 2018-19. Each collision cost more than $4,000. In Idaho, one out of every 106 drivers had a collision.

Nationwide, State Farm estimates there were more than 1.9 million animal collision insurance claims in the U.S. between July 1, 2018, and June 30, 2019.

Washington and Idaho’s numbers pale in comparison to some eastern states, Hansen said.

“I’ve worked on deer in Indiana. I’ve worked all over the country,” she said. “The road density is a lot higher than we have here. And the whitetail density is a lot higher.”

She urges drivers to be vigilant, drive slower — particularly at night — and remember, if you see one deer, there is likely another behind it.

Highway 395 north of Spokane is one of the “hottest areas” in the state, she said. That’s likely due to the relatively high volume of traffic and the presence of agriculture, which attracts deer and other animals as snow and cold weather make the hills and mountains inhospitable. Wildlife crossings, such as the ones along I-90 near Snoqualmie Pass, likely wouldn’t have much impact, she said. Those types of crossings are most effective along dedicated migration corridors.

The collisions can have real impacts, both on deer populations and hunting opportunity. In 2009, vehicle collisions prompted wildlife officials to reduce hunting opportunity.

“Every animal that doesn’t get hit by the car is one that is still out there on the landscape and it’s also one more that is available for hunters to go after and eat,” Hansen said.