Notes from the Field: Evidence-Based Practice
Employing Evidence to Combat Everyday Tragedy
Captain Ken Clary, Iowa State Patrol
February 15, 2019
Imagine waking up, turning on your local news, and learning that a 747 airplane has crashed nearby, killing everyone on board. As the carnage is totaled, you are shocked to learn that 411 people died in the crash. Now imagine it happens again just four days later in a neighboring state with the same death toll, and then again four days later in yet another state. Imagine the outrage that would follow – the public shock and demand for answers from the media, the public, and Congress. Now try to envision this continuing, with 411 deaths every four days for an entire year in airplane crashes throughout the nation.
As unimaginable as it may seem, that death toll mirrors what occurs on U.S. roadways. Every year, traffic fatalities are among the leading causes of non-health-related deaths in the United States. According to the National Highway Traffic Safety Administration (NHTSA), 37,461 lives were lost in motor vehicle crashes on U.S. highways in 2016. Yet unlike airplane crashes, fatal motor vehicle crashes garner little attention except from those directly affected.
About "Notes from the Field"
NIJ has launched the “Notes from the Field” series to allow leading voices in the field to share their strategies for responding to the most pressing issues on America’s streets today.
Similar to airplane crashes, fatal motor vehicle crashes are thoroughly investigated. The NHTSA compiles fatal motor vehicle crash data and has determined that 94 percent of fatal crashes could have been avoided by simply changing human behavior. Although the exact location of future fatal crashes is difficult to pinpoint, investigations allow us to identify with some certainty the cause of fatalities in crashes year after year. Leading causes include distracted driving, operating under the influence of alcohol and drugs, not wearing a seatbelt, and speeding.
Historically, law enforcement agencies have deployed analysis and technology to reduce traffic crashes. Often they do this by utilizing historical crash data and targeting enforcement efforts in areas where there is a higher propensity for crashes to occur (i.e., Data-Driven Approaches to Crime and Traffic Safety, or DDACTS). Such approaches are often effective in high-population areas, but on rural roadways, crashes may not regularly cluster at discrete locations. Given that approximately 70 percent of fatal crashes occur on rural roadways, it’s important to explore other, less conventional ways of changing human behavior.
One telling example of how human behavior can have a direct impact on lives lost involves seatbelt usage. Over 92 percent of Iowans wear a seatbelt, yet the remaining 8 percent account for more than 42 percent of those killed in traffic crashes. If we could simply get the remaining 8 percent to buckle their belts before they begin the journey that leads to the crash site, we could dramatically reduce traffic fatalities.
An Alternative Approach
Identifying law enforcement activities that deter and prevent fatal accidents has profound effects on traffic safety and may be useful in rural areas, where traffic crash events are more spread out. This year, the Iowa State Patrol and George Mason University’s Center for Evidence-Based Crime Policy partnered to develop a place-based, proactive, and problem-oriented strategy, with the goal of increasing the public’s perception of law enforcement presence and thus significantly reducing traffic crashes, injuries, and fatalities in Iowa.
Unlike other strategies that focus on where crashes might cluster (e.g., DDACTS), the Iowa State Patrol and George Mason University analyzed 10 years of crash data to identify potential “hot towns” near crash sites as likely origin points for drivers involved in fatal crashes along Iowa’s rural roadways. Analysis of data and crash reports suggests that victims of serious injury and fatal crashes visit these towns, become intoxicated with drugs or alcohol, and then unsafely operate their vehicles (e.g., speeding, seatbelt violations). Research tells us that the perception of a police presence is as important as the presence itself in deterring crime. When impaired citizens drive home from bars in rural Iowa, they take a calculated risk that they won’t encounter police, based on their perception that the police don’t have a major presence in these areas.
In an effort to combat this perception, we have implemented community policing efforts that target both the hot spot road segments for crashes and the activity hot spots within the nearby localities that serve as likely origin points for the drivers. Troopers make 10- to 20-minute visits to each hot town, engaging in highly visible citizen interactions at specific locations — such as bars, gas stations, and convenience stores — before moving to the next hot spot. These engagements revolve around serving patrons responsibly, ensuring everyone has made arrangements to get home safely, and providing patrons with safety messages, including the importance of wearing seatbelts.
Trooper visits include leaving behind literature in convenience stores and other high-volume citizen areas (specifically, literature regarding the leading causes of fatal crashes, such as distracted driving, operating under the influence of alcohol and/or drugs, not using a seatbelt, and speeding). When they patrol in hot spots, troopers have high-profile, often somewhat unexpected interactions with citizens. The majority of these interactions are nonpunitive and positive; they serve a dual function of deterring accidents and also improving the perception of a state police presence in the community. This can be as simple as a conversation or a traffic stop, but it can leave a lasting impression on the community.
The hot towns strategy is grounded in both problem-solving research and research showing that periodic and unexpected short visits to hot spots are an effective and efficient means of controlling crime and disorder. Based on the deterrence literature, all of these approaches are intended to create a “media” presence; word spreads in these places of increased police interest and presence, reducing serious and fatal vehicle crashes. This approach, in addition to enforcement activities, provides an extra problem-solving layer to get at the root of fatal crashes. Hand-in-hand with these tactics, we use analysis to identify strategic locations of the origins and pathways to crash sites. All of these interactions are intended to get people to see and talk about trooper actions with others. This increases perceptions of a law enforcement presence, even though troopers may visit hot spot origin locations only for short periods of time. In addition to driving down traffic fatalities, increasing the perception of a police presence may also prevent additional crimes.
Proactive Over Reactive
Our strategy in Iowa is a unique approach to traffic enforcement because it is both proactive and preventive — not reactive, as most traffic enforcement efforts tend to be. Our short-term data tell us that since implementing these tactics, traffic fatalities have fallen. We’re working with George Mason researchers to collect a variety of performance measures for this multiyear project and ultimately conduct a rigorous evaluation of the intervention.
Although traffic crashes don’t garner the media attention of other tragic events, their annual impact is significant. Through the implementation and study of this new science-based, multifaceted law enforcement-citizen interaction, we can identify ways to change human behavior to reduce traffic fatalities. In pairing the research with practitioners’ on-the-ground knowledge, this evidence-based strategy is working to save lives in rural communities.
About “Notes from the Field”
The National Institute of Justice (NIJ) is the research, development, and evaluation arm of the U.S. Department of Justice. NIJ aims to address the critical questions of the criminal justice field, particularly at the state and local levels.
NIJ Director David Muhlhausen developed the “Notes from the Field” series to allow leading voices in the field to share their strategies for responding to the most pressing issues on America’s streets today.
“Notes from the Field” is not a research-based publication. Instead, it presents lessons learned by law enforcement executives and other on-the-ground leaders, from years of experience and thinking deeply about law enforcement issues.
About the Author
Ken Clary is a captain with the Iowa State Patrol, currently serving as an area commander responsible for four district offices that encompass approximately one quarter of the state. He earned a master of public administration degree from Upper Iowa University and is a graduate of the FBI National Academy (269th Session), an NIJ LEADS scholar, and an executive fellow for the Police Foundation.
Writing and editorial support was provided by Rianna P. Starheim, a writer with a federal contractor, on assignment at the National Institute of Justice, U.S. Department of Justice.
[note 1] U.S. Department of Transportation, National Highway Traffic Safety Administration, Traffic Safety Facts 2016: A Compilation of Motor Vehicle Crash Data from the Fatality Analysis Reporting System and the General Estimates System, DOT HHS 812 554, May 2018, https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/812554.
[note 2] U.S. Department of Transportation, National Highway Traffic Safety Administration. (2018). Traffic safety facts: 2016 data. Retrieved from
[note 3] NIJ’s CrimeSolutions.gov gave DDACTS a Promising Program rating in 2016. See the
DDACTS program profile, posted July 11, 2016.
[note 4] NIJ’s CrimeSolutions.gov gave DDACTS a Promising Program rating in 2016. See the
DDACTS program profile, posted July 11, 2016.
[note 5] Ibid. See also 2016
Crash Facts, Iowa Department of Transportation, Motor Vehicle Statistics and Research Studies.
[note 6] D.S. Nagin, R.M. Solow, and C. Lum, “Deterrence, Criminal Opportunities, and Police,” Criminology: An Interdisciplinary Journal 53 no. 1 (2015): 74–100.
[note 7] C.S. Koper, “Just Enough Police Presence: Reducing Crime and Disorderly Behavior by Optimizing Patrol Time in Crime Hot Spots,” Justice Quarterly 12 no. 4 (1995): 649–672.
[note 8] L.W. Sherman, “Police Crackdowns: Initial and Residual Deterrence,” Crime and Justice 12 (1990): 1–48.
Date Created: February 15, 2019