We all want to minimize deer-vehicle crashes.
How can we best do that?
(Data from the Michigan State Police Traffic Crash database compiled on MichiganTrafficCrashFacts.org unless otherwise noted.)
Fact: Culling doesn't decrease deer-vehicle crashes.
Jackson, MI has culled for nearly a decade. Yet Jackson still remains one of the worst counties in the state for deer-vehicle collisions. A study by the Virginia Department of Transportation concluded that reducing the deer population does not reduce deer-vehicle collisions.
Fact: Ann Arbor deer-vehicle crashes have been decreasing.
Though the total number of general vehicle crashes in Ann Arbor has been increasing (possibly due to more people being on the road), the percentage of deer-related vehicle crashes has been decreasing over the last few years, with the odd exception of 2015 (the year of the first Ann Arbor deer cull). That odd exception does not exist in surrounding communities:
And state-wide, deer-vehicle collisions have declined, too; in 2010, 19.8% of all Michigan crashes were deer-related. In 2019, 17.7% were.
Fact: Ann Arbor drivers should be more scared of bicycles.
Nearly every year, Ann Arbor has had more vehicle crashes with bicyclists than deer. This has resulted in 3 deaths by bicycle, but there have been no deer-related deaths in Ann Arbor. And while we'd all like to keep deer-vehicle collisions to a minimum, it's important not to fear monger. The facts reveal that some people are overstating the "threat" of deer. For the past decade, Ann Arbor averages fewer than 2 injuries/year resulting from a deer/vehicle collision. To put it in context: When driving in Ann Arbor, you're more likely to hurt a bicyclist than get hurt by a deer. And you're much more likely to get in a crash with someone who is under the influence of drugs or alcohol.
Fact: We know where deer-vehicle collisions happen in
Ann Arbor, and can help in non-lethal ways.
Maps of Ann Arbor deer-vehicle crashes reveal most are in the same spots, year after year.
Click on the maps to see where Ann Arbor deer crashes have been. Maps extracted from the City's report.
Fact: The most proven, cost-effective way to reduce deer-vehicle collisions is fencing.
If we want to reduce deer-vehicle collisions even further, experts say the best way is fencing. Others mention signage, lighting and trimming brush from the roadways, and reducing the speed limit where deer-vehicle collisions have happened/during the time collisions are most likely to happen (October-December).
In the Federal Highway Administration's Report to Congress focused
on the reduction of wildlife-vehicle collisions (as published on deercrash.org), they concluded by recommending implementation of three measures which were both effective and cost-effective: public information and education; wildlife fencing; and underpasses/overpasses with fencing.
A summary study by the University of Nebraska on Deer-Vehicle Collision (DVC) prevention techniques says, "multiple studies have shown properly installed and maintained fences combined with wildlife crossings to be the most effective method of reducing DVCs."
A paper by Wildlife Control at Cornell analyzing wildlife crash prevention methods and their effectiveness says, "Fencing, combined with underpasses and overpasses as appropriate, is the only broadly accepted method that is theoretically sound and proven to be effective."
The Deer-Vehicle Crash Information Clearinghouse (DVCIC) states, "Only studies of properly installed/maintained exclusionary fencing and wildlife crossing installations have consistently shown DVC reductions. The DVC reduction capabilities of the other 14 countermeasures [including herd reduction] appear to still be in question."
Rochester Hills also reports that education ("Don't Veer for Deer") and attention to signage (periodically looking where "deer crossing" signs are and adjusting as needed) have helped their community reduce DVCs, too. Ann Arbor will reportedly be implementing some of their education practices.
Though signage has shown limited effects in some studies, Minnesota piloted a flashing sign system notifying drivers when deer were present, and they reported significant reductions in DVCs in years following.