Background
Motorcycle-animal collisions have been described in several small case series. The true burden of these collisions remains unknown.
Objective
The aim of this study is to determine rates of injury and fatality among motorcycle-animal collisions in the Midwest.
Methods
A retrospective cohort of motorcycle-animal collisions occurring from 2004 to 2010 (n = 4941) was created from existing data extrapolated from the Michigan Traffic Crash Facts Database, the Wisconsin Department of Transportation, and the Minnesota and Ohio Departments of Public Safety. Motorcycle registrations were collected from the Federal Highway Administration. Estimates of deer populations were collected from the respective state Departments of Natural Resources.
Results
A total of 184 fatal (Michigan 25.5%, Wisconsin 34.2%, Minnesota 16.3%, and Ohio 23.9%) and 4757 nonfatal (Michigan 45%, Minnesota 17%, and Ohio 38%) motorcycle-animal collisions were reported between 2004 and 2010. These states represent 16.2% of all motorcycle registrations in the United States, and that number has increased each year. Deer populations have a nonsignificant downward trend (5.32 to 4.97 million). Overall collision rates per 100 000 registered motorcycles have not changed (81.1 to 73.0). Among individual states, collision rates decreased in Minnesota (64.2 to 46.3, P = .002, R2 = 0.87), and Michigan had the highest mean collision rate (121.7, SE 10.5). Total injuries (79.2%) and fatalities (3.22%) were equivalent to nonanimal-motorcycle collisions (79.4% and 3.58%, respectively). Injury rates per 100 collisions have remained stable (77.1 to 79.8). Fatalities rates per 100 collisions have a nonsignificant downward trend in Ohio and upward trends in Minnesota and Michigan. The overall mean fatality and injury rates per 100 collisions are 3.8 (SE 0.25) and 79.2 (SE 1.25), respectively.
Conclusions
Rates of motorcycle-animal collisions, fatalities, and injuries have remained stable in the Midwest. Collision rates have decreased in Minnesota, but injury and fatality rates have upward trends. Further efforts to decrease interactions between animals and motorcycles should be pursued.