Examining the Impact of Seattle Police Department’s Traffic Stop Restriction Policy on Driving Under the Influence and Drug Crime Incidents

Abstract

Police traffic stops for minor violations have gained considerable attention among scholars and advocates, and some research has found evidence of racial disparities in who is stopped for certain traffic violations. Recognizing the potential for racial disparities and other issues, various jurisdictions have sought to limit traffic stops. On January 14, 2022, the Seattle (Washington) Police Chief Adrian Diaz stated that the Seattle Police Department (SPD) would discontinue stopping individuals for various traffic violations. While these policies were enacted in part to reduce racial disparities and other outcomes that may flow from such stops, some have argued that limiting stops may lead to increased crime rates and traffic accidents due to the reduced investigatory reach of law enforcement. Another possibility is that some crimes, which may have been discovered during a routine traffic stop, could go undetected after a jurisdiction implements a traffic stop restriction policy. The current study explored whether the Seattle traffic stop restriction policy resulted in a decrease in the number of driving under the influence (DUI) and drug crime incidents. The results did not show statistically or substantively significant declines in the number of DUI or drug crime incidents in Seattle after the implementation of the traffic stop restriction policy. Replication is recommended before strong conclusions are drawn.

Keywords: routine traffic stops, traffic stop restriction policies, driving under the influence, drug crime, policing, time series, Seattle