Deer Crashes: Are there hotspots?
(Photo taken South of Humbird, Wisconsin on Highway 12)
Introduction
Wisconsin ranks 7th in the United States when it comes to deer crashes, and Wisconsin residents have a 1 in 57 chance of hitting a deer (State Farm, 2020). In 2019, there were over 18,414 deer crashes across the state of Wisconsin (Community Maps, 2021). The average cost of a deer crash was $3,362 (Taschler, 2018). There are some stretches that seem to have more deer crashes than others. Are these crashes random or are there hot spots? This project investigated if deer crashes are random or if there are hot spots.
Preliminary Research
The first step was to see if there has been previous research into this. Since deer crashes are extremely common, there are millions of research reports on deer crash statistics. But there were some articles that were the most helpful.
The first one was a research project that researched if the deer in the Czech Republic were being hit in common areas. The researchers mapped out each location and tried to find hot spots. Their project also found that topography also played a role in creating hot spots. This also showed them that crashes can happen with a pattern that can be measured (Nezval, 2020).
The second article was from a project completed in South Carolina. They also noticed a stretch of road that seemed to have many crashes to it. After an investigation, they did find out that there was a stretch that did have a higher rate of crashes and did have hot spots. They found this out by mapping out every location and then running a cluster analysis (Malhotra,1996).
Another interview that was conducted by Aaron Dekker with Jeff Pritzl, a deer specialist from Wisconsin DNR, also shed some light on deer behavior. His response was that “Deer are creatures of habit. You can see this with deer paths in the woods. Their average range is about one square mile.” (Pritzl, 2021)
Figure P1
Figure P1: The deer path is highlighted in green. This is what Mr. Pritzl was talking about as proof that deer are creatures of habit. This one was found crossing a road. Next time a deer gets hit, look for a deer path.
Background.
This project was inspired by a deer crash that happened to the author in June 2020. There were also previous times when a deer almost was hit. Deer crashes can also happen to people who either live in rural areas or drive through rural areas. Personal experience is what led to the desire to start this project, but also the desire to help other people avoid a possible deer crash was the other.
Figure B1
Figure B1: shows what can happen when a deer crashes into a car.
Methods
Figure M1:
Figure M1: This figure shows the project’s flowchart.
The first goal was to find deer crash data in Wisconsin. The website Community Maps published the data of deer crashes, it is a project with UW-Madison and Wisconsin sheriff's Departments for mapping all crashes in the state of Wisconsin. Unfortunately, they would not give me the latitude and longitudes on a spreadsheet. The next step was finding the latitudes and longitudes on Google Earth.
2019 was picked because in 2020 Wisconsin was on lockdown and that cut down on deer crashes (Community Maps, 2021). In Community Maps, it showed that statewide there was a drop of 2000 crashes. That was enough of a drop that it was decided that getting hot spots from that would not be as easy or nearly impossible.
To be considered a hot spot, there needed to be at least three crashes in 2019 within a half mile of each other. A half mile was picked to be the hot spot distance because if there are more than three crashes in a half mile stretch that would be considered higher than normal. Half mile would also indicate a possible halfway point of a deer range.
Arc GIS pro was the mapping program that was used. The reason is that at UW-Eau Claire Geography department was encouraging students to complete work in Arc GIS pro. But it can also be completed in Arc Map 10.8.
The goal now is to find the answer to if hot spots do exist for deer crashes. The methods above will be used to confirm or reject the hypothesis. The hypothesis is that while some crashes are random, there are hot spots.
Criteria for selection
The three counties that were selected, for simplicity, had to fit a few criteria.
Must be in Wisconsin.
Must have a Four Lane highway running through it.
Must be in different deer zones.
Figure M2
Figure M2: Shows the DNR map of deer zones. (Wisconsin, 2020)
Figure M3
Figure M3: Shows what Community maps should have looked like after:
For the Counties tabs: Select “Iowa or Jackson or Washburn” County.
Date Range: Select “2019 January to 2019 December”.
Leave Crash Severity and Crash Flags fields blank.
Deer Flag: Select “Deer Crash Only”
Figure M4:
Figure M4: This figure shows what the partial spreadsheet would have looked like at completing data transfer.
Figure M5:
Figure M5: Shows what the technique used Defined Distance Scan image was. The Input features were the county crash points and Output features were the name of the output.
Figure M6:
Figure M6: This was completed by filling in the buffer tool setting. The input features were the Crash Points, and the Output features Class was the name of the county half mile.
Results
Iowa county Results
Figure R1
Figure R1: This figure shows Iowa County’s deer crash hot spots with the half mile buffer.
Jackson County Results
Figure R2
Figure R2: This figure shows Jackson County’s deer crash hot spots with the half mile buffer.
Washburn County Results
Figure R3
Figure R3: This figure shows Washburn County’s deer crash hot spots with the half mile buffer.
Discussion
Iowa County’s hot spots follow an interesting pattern as seen in (See Fig. R1). The first hot spot was north of Dodgeville near Governor Dodge State Park on Highway 23. This was unusual since Highway 23 is a two-lane highway at that point. The hypothesis is that the state park likely has something to do with it. There was another hot spot near Barneveld on Highway 151. There was also a hot spot on Highway 18 west of Dodgeville. Then east of Dodgeville on Highway 151 was one right outside of the city. The final hot spot was north of Mineral Point on Highway 151.
Jackson county’s hot spots followed an expected pattern as seen in (See Fig. R2). It was expected that I-94 would have many hot spots scattered along the route. The unexpected pattern was how most of them were north and west of Black River Falls. There is also a cluster just east of Black River Falls on Highway 54. The rest of the county did not have any other hot spots.
Washburn County’s hot spots had three main ones (See Fig. R3) on the stretch of highway 53 that was predicted. One hot spot was just south of Sarona. One hot spot was just north of Trego. Another is just south of the northern county line. It was noteworthy that Highway 63 had no hot spots on it in 2019.
Across the three counties, there were some patterns that were common. The first pattern was that almost all hot spots occurred on four lane highways. This pattern could be explained by high traffic counts or that area is just a common place for deer crashes. The hot spot north of Dodgeville near the State Park was a rarity on two lane highways. Jackson County had one hot spot on a two-lane highway, but it also was right off the interstate. Washburn County did not have any hot spots on their two-lane highways. One was expected on Highway 63 heading towards Hayward. That was the major surprise was how there were little to no hot spots on two lane highways.
Limitations.
The first limitation was the accuracy of reporting deer crashes. Sometimes where the deer got hit and the place it was reported are not always correct. Or sometimes the crash does not even get reported to start with. Those were the two were the main limitations. More points would have either showed a clear hot spot pattern or would have signaled that there are no hot spots.
Future Projects
A future project could be to see if the topography around the crash sites has a role in crashes. During the half mile radius checks, it was noticed that certain topographical features were more common than others. It would be a great project to see if certain topographical features do make crashes more likely.
It would also be telling to see how traffic counts play a role in hot spots. There were some stretches of two-lane highways that seemed to have way more crashes in a half mile radius than some four lane highways. The other thing to do with traffic counts would be to calculate the percent chance of hitting a deer on a stretch of road.
Acknowledgments
Dr. Matt Haffner, Professor of Geography at UW-Eau Claire, was a major help in this project. Early on, I entered the latitude/ Longitude incorrectly. Dr. Haffner wrote a code to fix that error (Haffner). Without him doing that, this project would have stalled out and probably would have never been completed. He also was my mentor in other projects at UW-Eau Claire.
Conclusion
In conclusion, my hypothesis was proven correct. It appears while some crashes are random, there are hot spots. This would indicate that there are stretches of roads that are more prone to deer crashes. Jeff Pritzl indirectly predicted that there would be hot spots because of deer being creatures of habit. After reading this paper, hopefully now drivers can either avoid deer crash hot spots or be ready for a potential crash.
Works Cited
- Community Maps - Crash. https://transportal.cee.wisc.edu/partners/community-maps/crash/search/BasicSearch.do;jsessionid=00556FBC56703952046F7E82DA0AE5A2 (last accessed 1 May 2021).
- Haffner , M. 2021. Convert DMS to DD ($2110450) · Snippets · Snippets. GitLab. https://gitlab.com/-/snippets/2110450 (last accessed 4 May 2021).
- Malhotra, R., P. E. Johns, M. Madden, and G. Wein. Deer-Vehicle Collisions: Is There a Pattern? https://proceedings.esri.com/library/userconf/proc00/professional/papers/PAP446/p446.htm (last accessed 2 March 2021).
- Nezval, V., and M. Bíl. 2020. Spatial analysis of wildlife-train collisions on the Czech rail network. Science Direct https://www.sciencedirect.com/science/article/pii/S0143622820304835 (last accessed 2 March 2021).
- Pritzl, J. 2021. Deer Behavior.
- State Farm.S. F. S. 2020. Where are Animal Collisions Most Likely? - State Farm®. State Farm. https://www.statefarm.com/simple-insights/auto-and-vehicles/how-likely-are-you-to-have-an-animal-collision (last accessed 11 May 2021).
- Taschler, J. 2018. Every day, a car hits a deer in Wisconsin. This week is among the most dangerous on our roads. Milwaukee Journal Sentinel. https://www.jsonline.com/story/money/business/2018/11/08/deer-crashes-wisconsin-peak-november/1847638002/ (last accessed 4 May 2021).
- Wisconsin DNR Deer Zone Map. 2020. https://dnr.wisconsin.gov. https://dnr.wisconsin.gov/sites/default/files/topic/images/dmz%20%281%29.png (last accessed 4 May 2021).
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