Traffic stops do not prevent traffic deaths

Abstract

Objectives: Amid growing calls for police reform, it is imperative to reassess whether police actions designed to improve public safety are associated with injury prevention. This study aims to examine the relationship between the police traffic stops (PTSs) and motor vehicle crash (MVC) deaths at the state level. We hypothesize that increased PTSs would be associated with reduced MVC deaths.

Methods: We retrospectively analyzed PTSs and MVC deaths at the state level from 2004 to 2016. Police traffic stops data were from 33 state patrols from the Stanford Open Policing Project. The MVC deaths data were collected from the National Highway Traffic Safety Administration. The vehicle miles traveled data were from the Federal Highway Administration Office of Highway Policy Information. All data were adjusted per 100 million vehicle miles traveled (100MVMT) and were analyzed as state-level time series cross-sectional data. The dependent variable was MVC deaths per 100MVMT, and the independent variable was number of PTSs per 100MVMT. We performed panel data analysis accounting for random and fixed state effects and changes over time.

Results: Thirty-three state patrols with 235 combined years were analyzed, with a total of 161,153,248 PTSs. The PTS rate varied by state and year. Nebraska had the highest PTS rate (3,637/100MVMT in 2004), while Arizona had the lowest (0.17/100MVMT in 2009). Motor vehicle crash deaths varied by state and year, with the highest death rate occurring in South Carolina in 2005 (2.2/100MVMT) and the lowest in Rhode Island in 2015 (0.57/100MVMT). After accounting for year and state-level variability, no association was found between PTS and the MVC death rates.

Conclusion: State patrol traffic stops are not associated with reduced MVC deaths. Strategies to reduce death from MVC should consider alternative strategies, such as motor vehicle modifications, community-based safety initiatives, improved access to health care, or prioritizing trauma system.

Level of evidence: Retrospective epidemiological study, level IV.