Pennsylvania State Police Unveils Results of Traffic Stop Study

Hershey, PA - Today, the Pennsylvania State Police (PSP) and Dr. Robin Engel, Senior Vice President of the National Policing Institute, presented an analysis of data collected from all trooper-initiated traffic stops in 2022 across the Commonwealth. The data collection program is designed to identify patterns and trends in traffic stops and outcomes, and identify opportunities for improvement in policy, training, and supervision. Dr. Engel is a leading academic in the field of criminal justice and criminology, with expertise in empirical assessments of police behavior, police use of force, and police-community relations.

"Dr. Engel and her research team analyzed demographic and other information gathered from more than 440,000 trooper-initiated traffic stops last year," said Colonel Christopher Paris, Commissioner of the PSP. "The data shows our department has made great progress in these outcomes over the years, and we're proud of the work our troopers continue to do. We appreciate the partnership with the National Policing Institute as we move forward with one of the most comprehensive and high-quality data collection efforts in the country."

"The Pennsylvania State Police should be commended for reestablishing their comprehensive, voluntary data collection system, and these findings should inspire confidence among Commonwealth residents toward the leadership and Troopers of the Pennsylvania State Police," Dr. Engel said.

Among the key findings from the 2022 data analysis is that variables such as the reason for the stop and evidence discovered are the strongest predictors of post-stop outcomes, such as warnings, citations, arrests, and discretionary searches. The report showed no detectable, substantive racial or ethnic disparities in warnings, citations, or arrests during traffic stops.

Dr. Engel added, "PSP's rate of contraband seizures during discretionary searches is among the highest in the nation. Our review of the PSP's criminal interdiction training also suggests that their focus on both effective and equitable practices is a promising approach and serves as a national model."

"This data is a valuable tool in our toolbox as we strive to carry out our duties with integrity, respect and trust in accordance with our department's core values," added Colonel Paris. "Coupled with continued improvements in training, and our enhanced, more user-friendly, citizen complaint procedures, this data will help guide us as we provide the professional police services that residents of this Commonwealth not only expect but deserve."

The Pennsylvania State Police became one of the first police agencies to voluntarily collect traffic-stop information when the department first partnered with Dr. Engel in 1999 and continued voluntary reporting of traffic stops through 2010. The PSP reinitiated robust data collection in 2021 for all trooper-initiated traffic stops, with the initial year of the program focused on improving data collection and addressing data quality issues when identified.

Established in 1970, the National Policing Institute (formerly the National Police Foundation) is the oldest nationally known, nonpartisan, nonprofit, non-membership independent research organization dedicated to pursuing excellence through science and innovation in policing. As the country's oldest police research organization, the National Policing Institute has learned that police practices should be based on scientific evidence about what works best, the paradigm of evidence-based policing.

The 2022 CDR report is available online at

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Media Contacts

Adam Reed

State Police Media

Myles Snyder

State Police Media