Incidence and Injury Types in Motorcycle Collisions Involving Deer in Western New York

Chest, orthopedic, and head injuries were the most common injuries seen in deer–motorcycle collisions (Table). Head injuries, including the 1 patient who was confirmed to not have been wearing a helmet, accounted for 15.0% of the total injuries. This patient also had a longer length of stay at 19 days than the average of 6 days. Rib fractures were the most common injury, occurring in 20 (50%) patients. The 1 recorded fatality was the passenger of a patient who was dead at the scene.

Twenty-five (62.5%) patients in this series had injuries that are traditionally treated by orthopedic trauma surgeons, including scapular, clavicle, pelvic, and extremity fractures. Upper and lower extremity injuries occurred 10 (8.3%) and 15 (12.5%) times respectively, with the lower extremity injuries including long bone fractures, foot and ankle fractures, and 1 lower extremity traumatic amputation. Fourteen (35%) patients underwent one or more orthopedic surgical procedures.

Discussion

Although animal–vehicle collisions have been described in the literature, comparatively little data are available for the subset of animal–motorcycle accidents. This is an important gap considering that fatalities in collisions with animals were 6 times more likely to be persons riding motorcycles, although animal collisions are more common with other vehicles.⁶

Smoot and colleagues² also reported that motorcycle collisions with deer tend to result in a higher injury severity than collisions of other vehicles with deer. According to reports for Midwestern regions, motorcycle-versus-deer accidents are a significant problem, causing a large number of serious injuries as well as creating the financial burden of vehicle damage and medical costs.^2,3 However, the overall data are limited, and there is not much detailed information available for western New York.

Because of the large number of motorcyclists in New York State, it is important to consider accident data in this subset of the population. In 2010, 340,260 motorcycles were registered in New York State, with Erie County having the second highest number (21,745) of motorcycles registered.⁷ These numbers increased to 345,820 and 22,183 motorcycles, respectively, in 2011.⁸ In that year, the number of police-reported motorcycle accidents in New York decreased to 4855 from 5047 accidents in 2010, although both numbers are increased from 4647 accidents in 2009.^9-11 Despite the decrease in total police-reported motorcycle accidents from 2010 to 2011, the trend in motorcycle accidents involving an animal’s action has steadily increased from 313 (6.7%) in 2009 to 335 (6.6%) in 2010 to 401 (8.3%) in 2011.^9-11 Although these data from the New York State Department of Motor Vehicles are not further broken down by animal species, it can be reasonably surmised that most of these are caused by deer. This inference is supported by data from Bramati and colleagues⁴ showing that 81% of animal–vehicle collisions involved deer, as well as by the Wildlife-Vehicle Collision Reduction Study that showed deer were involved in 54.4% of animal–vehicle collisions in California and more than 90% of animal–vehicle collisions in Illinois and Minnesota.^4,12 These studies predominantly comprised collisions involving animals capable of causing substantial property damage on impact, such as deer or larger animals. This, along with the evidence of higher ISS seen in motorcyclists in deer-related traffic injuries,² supports the intuitive thought that motorcyclists are at increased risk for injury and fatality relative to other motor vehicles involved in accidents.

Williams and Wells¹³ reviewed 147 fatal wildlife–vehicle fatalities from 9 regions and found that the 2 most common fatalities were the motorcycle driver or passenger after striking an animal or an object. Jones¹⁴ also reported that the most common fatal wildlife–vehicle crashes involved motorcycles, as did fatal-accident reporting system data in the Wildlife-Vehicle Collision Reduction Study, which confirmed that approximately 30% of fatal crashes with animals involved motorcycles.¹²

Interestingly, the age of patients involved in motorcycle–deer collisions tends to be higher than that of patients involved in other motorcycle accidents. The numbers in our study reflect results in other study populations that suggest motorcycle riders who collide with deer are generally older than riders in other accidents who are more likely to be younger.⁴ One explanation is that younger riders may drive faster and more recklessly than older and experienced riders, resulting in an increased number of accidents unrelated to deer. Another consideration places younger drivers less commonly on roads where wildlife crashes more often occur (ie, roads that are rural, 2-lane).

Helmet use, when reported, was very high in our study population, most likely as a result of New York State’s mandatory helmet law for motorcyclists. Our data showed that more than 95% of patients whose charts documented helmet usage were wearing helmets at the time of the collision, compared with a Wisconsin study showing that only 29% of patients were wearing helmets.³ This may explain the proportion of head injuries in our study being 15.0% compared with the 29.5% in the Wisconsin study.³ Although both datasets involved a limited number of patients, the results suggest that mandatory helmet laws are effective in preventing head injuries. Also, the only patient in our study who was confirmed to have not been wearing a helmet had a much longer length of hospital stay than the average patient (19 vs 6 days). William and Wells¹³ found that 65% of motorcyclists killed in collisions with animals were not wearing helmets, and they believed that many of these fatalities could have been prevented with helmet use. Again, these limited data suggest the effectiveness of mandatory helmet use.