Introduction

This document was created by the Division of State Patrol Bureau of Transportation Safety and Technical Services (BOTSTS). The data is based on three-year (2018 - 2020) trends.

The intention of this document is to assist Traffic Safety Commissions to examine their own transportation safety issues within their respective county and to identify potential countermeasures. While these crash and driver behavior trends are examined at the county level, these trends can be examined at a more local level. BOTSTS can provide this analysis and data to your local municipality.

For requests, email BOTSTS at CrashDataAnalysis@dot.wi.gov.

Zero in Wisconsin

WisDOT has adopted Zero in Wisconsin, the belief that no one should be killed or seriously injured from using the road network. The aim of Zero in Wisconsin (otherwise known as Safe System, Vision Zero or Sustainable Safety) is for a world free from road fatalities and serious injuries.
The Haddon Matrix (below) models basic principles to be applied to safety analysis. Each cell of the matrix represents a different area in which countermeasures can be implemented to improve traffic safety. Countermeasures applied to the pre-crash phase are designed to reduce the number of crashes. Countermeasures that are applied to the crash phase would not stop the crash, but could reduce the number or severity of injuries that occur as a result. Countermeasures focusing on the post-crash phase optimize the outcome for people with injuries, and prevent secondary events. Learn more about this approach at the Federal Highway Administration and Zero in Wisconsin.


Transportation Safety

Alcohol and Drug-Impaired Driving

In Sauk County, 52 people are injured or killed in a crash involving a driver believed to be impaired by drugs or alcohol, in an average year. That is 33% of all persons killed in a crash. Statewide, this is 33% of all persons killed.



While 72% of drivers believed to be impaired by drugs or alcohol are male.

Hotspots of alcohol and drug-related crashes with an injury or fatality (2018 - 2020)






















Distracted Driving

In Sauk County, a driver being distracted is listed as a contributing factor in 12% of injury and fatal crashes. Statewide, this is 12% of injury and fatal crashes. Distracted driving is based on a two-year (2019-2020) trend due to a change in data fields. Below shows the breakdown of the factors in these distracted driving crashes.


Occupant Protection

Statewide seatbelt usage has been increasing over the past two decades. This past year experienced a usage rate of 89.2%, which is based on an annual seatbelt survey. Occupants not wearing a seatbelt are more likely to suffer a serious injury or fatality. Of the total statewide occupant fatalities, 1 out of 3 were not wearing a seatbelt. Statewide seatbelt usage rate reached an all time high in 2019.


People in your community can conduct their own seatbelt survey via the ‘Local Seatbelt Survey’ in the app store.


Bicyclist and Pedestrian Safety

In the last 3 years in Sauk County, 36 cyclists and 45 pedestrians were killed or injured in 73 crashes. The below two bar charts shows the contributing factors and where these crashes occurred.


A bike or pedestrian crash is more likely to happen in an urban area, however, a fatal or serious injury crash is more likely to occur in a rural area due to higher speeds and due to further distance from a trauma center.

Locations of injury and fatal bicycle crashes

Locations of injury and fatal pedestrian crashes






















Motorcycle Safety

In the last 3 years in Sauk County, 95 motorcyclists were killed or injured. Of these, 56% were not wearing a helmet.

Locations of injury and fatal motorcycle crashes

The type of helmet and other safety equipment worn, such as protective gear and gloves, can also impact the type of injury sustained.

92 motorcycle drivers were involved in a fatal or injury crash. 92% were Wisconsin drivers. Of these, 16% did not have a valid M endorsement.




























Teen and Older Drivers

In Sauk County, teen or older drivers make up 22% of drivers involved in a fatal or injury crash. Statewide, this is 19% of drivers in fatal and injury crashes.

Breaking this down for Sauk County:

  • 225 teen drivers make up 9% of drivers involved in a crash and make up 5% of licensed drivers and

  • 334 older drivers make up 14% of drivers involved a crash and make up 23% of licensed drivers.



Locations of injury and fatal crashes involving a teen driver Locations of injury and fatal crashes involving an older driver






















Lane Departure Crashes

More lane departure crashes occur in Sauk County, out of total injury and fatal crashes, compared to the state. That is an average of 155 fatal and injury lane departure crashes per year. Colliding with a Ditch/Culvert was the most frequent first harmful event. Breaking this up, 80% are single vehicle only, while statewide 75% are.

A lane departure crash is defined as when the driver crosses the centerline, edge line, or leaves the roadway and then usually colliding with another vehicle or an object, such as a guardrail or a tree. The cause of a lane departure crash could be a mixture of factors – speeding, being impaired by alcohol, or feeling tired.

Below shows the breakdown of the first harmful event in these lane departure crashes.


Speeding

Speeding includes both exceeding the speed limit and driving too fast for conditions. Speeding has a compounded affect in a crash; decreasing speed can reduce the crash risk, reduce injury severity, and make it possible to control the vehicle if an event were to occur. Of all fatal and injury crashes, 24% involved speed as a contributing factor resulting in 114 fatalities and injuries in an average year. Statewide, this is 20% of fatal and injury crashes.

Comparing to road type by lane miles, State roads are the most disportionate road type for fatal and injury speed crashes.

Crash Type 2016 2017 2018 2019 2020 Trend
Fatal 2 2 3 0 5
Injury 91 84 88 89 74
Property Damage 207 199 265 272 153
Total 300 285 356 361 232 -


Here are trends of all speeding-related crashes over the past 5 years.






1 out of 4 of all crashes where speed is a factor involves a young driver.

Hotspots and analysis areas of all crashes involving a speeding driver























Appendix

Predictive Analytics

Predictive Analytics is an emerging program that uses established crash trends to identify “hotspots” in a particular locality. The program is geared to promote changes in driving culture in and around crash hotspots, with a particular focus on outreach. Utilizing a Safe Systems Approach, Predictive Analytics introduces multi-pronged solutions that involves a wide array of partners and stakeholders in traffic safety working together to reduce injury crashes.

Hotspot Selection

A county or municipality may use whatever method they decide to select their own hotspots. But utilizing Community Maps, a jurisdiction can target areas that have a demonstrated history of injury crashes. For example, using the search components on the left give us the following map, with several hotspots to choose between: