Deer-vehicle collisions a problem with no easy solution

Dylan LightfootStaff

December 16, 2012

Roger Richardson of the Miller Insurance Agency in West Jefferson always expects a sharp increase in deer-related accident claims during the fall months — he’s been selling car insurance for 40 years.

But, in recent years, he said “it seems like its gotten worse.”

This season, his agency has been getting eight to 10 deer-vehicle collisions — DVCs, they call them in the transportation world — per week. Claims like these run about $1,000 minimum, Miller said, but deer impacts can easily cause $6,500 in vehicle damage.

The N.C. Department of Transportation reported more than 19,500 animal-related accidents in each of the last three years. Roughly 90 percent of those involved deer.

That number could be low. State Farm Insurance projected an estimate of 48,000 DVC’s for N.C.’s 6 million licensed drivers from July, 1 2011 to June, 30 2012.

In a 2012 press release, State Farm estimated one in 135 drivers in N.C. are likely to collide with a deer.

The Centers for Disease Control and Prevention finds that DVCs result in approximately 200 deaths per year nationwide, and cause $1.1 billion in damages.

Deer collisions are a big problem, but they are not news.

Dozens of articles on the Internet report rampant DVCs, as one region then another hosts the latest epidemic. Currently, Pennsylvania is seeing the worst of it, according to State Farm.

The reasons why are no mystery. “The main factors are more roads, more people, more traffic,” said biologist Mike Carraway, Mountain Region Supervisor for the N.C. Wildlife Resources Commission.

There are also more deer.

The NCWRC estimates the size of the state’s deer herd every five years. Over the past 25 years, the deer population has been steadily increasing.

One theory of deer population growth frequently offered in DVC news coverage is a nationwide decrease in the number of deer hunters. A survey sponsored by the U.S. Fish and Wildlife service found 1.5 million fewer licensed hunters from 1996 to 2006.

But even as a shrinking demographic, the same survey showed 304,000 hunters in N.C. hunted a total of 4.9 million days in 2006. And, Carraway said, while there may be fewer hunters, they are killing more deer than ever.

Total deer harvest registered with the NCWRC for 1985 was 55,074. In 2011, hunters bagged 173,553. Ashe County’s deer harvest for the same year was 2,683 — five deer per square mile of hunting land — up from 1,641 in 1996.

Poaching and predation also contribute to attrition in deer populations, Carraway said.

With more deer being killed by bullet and automobiles, population growth is puzzling. Carraway offers a counter-intutive explanation: humans are encroaching on their natural habitat.

“Every time a new housing development goes in, it creates a sanctuary,” said Carraway. “They provide good grassland forage, ornamental plants and forest cover.”

And, he said, hunters and predators are conspicuously absent on suburban and rural tract developments.

But there may be more to the issue than just increased traffic versus more deer.

A 2008 study from Utah State University surveyed the effectiveness of DVC prevention techniques, finding no definite link between deer population and number of collisions. The key factors are likely “differences in deer population densities and dynamics between study areas,” the study found.

The study recommened a combination of local population control, exclusion of deer from roadways, and modification of motorist behavior as the most promising strategy for reducing DVCs. Deer-proof fencing along roadways was found to be the single most effective technique.

Communities trying to reduce DVCs should lower speed limits, clear vegetation and other visual obstructions along roadways, and install effective signage, the study advised. A test of new animal-activated warning signals in Switzerland was found to reduce DVCs by 80 percent.

In-vehicle detections systems, such as Toyota’s Night View, offer drivers enhanced night vision, but their effectiveness in preventing DVCs has not been proven, the study read. Deer are nocturnal, so drivers should be most alert at night, when 80-90 percent of DVCs occur.

According to State Farm, motorists should use high beams at night, and be alert even when they spot deer not in the roadway — deer travel in groups, and others may be nearby. If possible, drivers should also resist the impulse to swerve to avoid hitting deer.

The CDC finds that 45 percent of animal-related accidents involve motorists swerving to avoid hitting an animal, and colliding instead with trees, poles and other vehicles.

Since the late seventies, deer whistles have been sold as a DVC prevention auto accessory. The devices cost $10-50, and claim to alert deer to approaching vehicles by emitting ultrasonic noise at speeds above 30 mph.

The USU study and others have shown deer whistles to be ineffective.