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A review of patrol techniques to reduce serious injury and fatality crashes

The FREE program has promise as a strategy for reducing vehicle crashes, particularly those stemming from dangerous driving behaviors


Photo/Iowa State Patrol Facebook

By Christopher Koper, Ph.D., Chief Ken Clary and Cynthia Lum, Ph.D.

In 2018 and 2019, the Iowa State Patrol (ISP) implemented the Fatality Reduction Enforcement Program (FREE) in collaboration with research partners from George Mason University (GMU). GMU’s evaluation suggests that the FREE program reduced crashes involving impaired driving in the program area by 18% in year one and may have contributed to more significant reductions in speed-related crashes. Law enforcement leaders may consider this approach to complement other strategies used to reduce unsafe driving behaviors and maximize traffic safety enforcement efforts.

About FREE

FREE is an evidence-based program designed specifically for use in rural areas that have higher risks of severe crashes and account for approximately 80% of vehicle fatalities in Iowa. FREE was implemented in a rural section of Iowa encompassing 28 counties, 16,000 square miles, and a population of roughly 650,000.

The program concentrated on changing driving behaviors at road segments with a high risk for crashes and activity hot spots (i.e., local towns) that serve as likely origin points for drivers involved in crashes. Officers conducted intermittent, high-visibility patrols in these locations, complemented by preventive community contacts stressing safety messages at places such as bars, gas stations, and convenience stores. These activities were intended to promote deterrence, community engagement and police legitimacy while also addressing the broader opportunity structures and behaviors (such as alcohol and drug use, speeding and failure to wear a seatbelt) that contribute to vehicle crashes and fatalities.

Location selection

Target locations were selected based on an ISP analysis of fatal crashes during the preceding 10 years, which showed that most of these crashes occurred within a few miles of the selected towns. Troopers concentrated their town visits (which were about 20 minutes in duration) during the late afternoon and evening hours (3 p.m. to 1 a.m.) and their visits to high-risk roadways outside the towns (which were typically 30-45 minutes) during daytime hours (6 a.m. to 4 p.m.). The participating troopers were each assigned to several locations and instructed to visit these locations periodically during their discretionary time (i.e., when not responding to calls for service). The program did not require overtime funding or for the participating troopers to be diverted from other duties.

Year one evaluation

In year one (2018), ISP utilized a small group of volunteer troopers (16) for these targeted enforcement activities on a nearly full-time basis. Five local police agencies also participated in the program in 2018, complementing troopers’ efforts in some of the larger hot spot towns. In year two (2019), ISP expanded the program to include all troopers and supervisors in the area (78) on a one-hour-a-day basis for the same activities. Year one resulted in nearly 10,000 interventions, while year two resulted in over 30,000 interventions spread over more towns and roadways.

GMU’s evaluation suggests that FREE reduced crashes involving impaired driving in the program area by 18% in year one and may have contributed to more significant reductions in speed-related crashes. Despite the higher overall activity level in year two, FREE appeared more impactful in year one because activities were better focused on the highest-risk towns and times. The participating troopers and local officers also placed a greater emphasis on community engagement and prevention in the initial phase.

During year one, participating troopers and officers were most effective in preventing crashes in counties where they conducted more total and town patrols, did more traffic enforcement, made more bar and restaurant visits, and did more community engagement. Although the program did not substantially affect crashes overall in year two, trends were better in places where troopers did more community engagement, particularly in the form of visiting bars and restaurants.

Broader implementation

Efforts like FREE have promise as a strategy for reducing vehicle crashes, particularly those resulting from dangerous driving behaviors like speeding and driving under the influence of drugs or alcohol. Increasing patrol visibility and preventive community contacts in towns that are active and driver-origin hot spots can maximize the impact of traffic safety efforts in rural areas.

Proactive, informal contacts to encourage safe driving behaviors are also helpful, mainly in settings like bars and restaurants where people may be especially receptive to these messages. Law enforcement leaders may consider this approach a complement to others (like sobriety checkpoints and roadside surveillance) commonly used to reduce driving under the influence and other unsafe driving behaviors.

A more detailed report of this program and its outcomes is available below:

The Iowa State Patrol Fatality Reduction Enforcement Effort (FREE) by epraetorian on Scribd


Koper CS, Lum C, Wu X, Goodier M, Clary K. (2021.) The Iowa State Patrol Fatality Reduction Enforcement Report (FREE): Summary Evaluation Report. Report to the International Association of Directors of Law Enforcement Standards and Training Fairfax, VA: Center for Evidence-Based Crime Policy, George Mason University.

About the authors

Christopher S. Koper, Ph.D., is an associate professor in the Department of Criminology, Law and Society at George Mason University and the Principal Fellow of George Mason’s Center for Evidence-Based Crime Policy.

Ken Clary was sworn in as the police chief in Bellevue, Nebraska, (the third largest city in the state) on September 1, 2020. As chief, he oversees a department of approximately 111 sworn and 15 civilian personnel.

Cynthia Lum, Ph.D., is University Professor of Criminology, Law and Society and director of George Mason University’s Center for Evidence-Based Crime Policy. She is a leading authority on evidence-based policing, an approach that advocates that research, evaluation, and scientific processes should have “a seat at the table” in law enforcement policymaking and practice.

Established in 1970, the National Policing Institute, formerly the National Police Foundation, is an independent, non-partisan, and non-profit research organization, sometimes referred to as a think-tank, focused on pursuing excellence in policing through science and innovation. Our research and applied use of research guide us as we engage directly with policing organizations and communities to provide technical assistance, training, and research and development services to enhance safety, trust, and legitimacy. To view our work, visit us at