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Micro Places – Wheeler & Phillips (2018)

Study Reference:

Wheeler, A. P., & Phillips, S. W. (2018). A quasi-experimental evaluation using roadblocks and automatic license plate readers to reduce crime in Buffalo, NY. Security Journal, 31(1), 190-207.

Location in the Matrix; Methodological Rigor; Outcome:

Micro places; Focused; Proactive; Rigorous; Mixed findings

What police practice or strategy was examined?

Automatic license plate readers (ALPRs) were used with a temporary roadblock deployment at 45 locations. Different roadblock positions were set up every day for two months at high crime intersections for 90 minutes. Five locations were targeted twice, and three locations targeted four times for a total of 60 individual roadblock operations. The roadblock funneled traffic past the ALPR and officers stopped any vehicles which the ALPR flagged. All other traffic was not stopped and was permitted to pass.

How was the intervention evaluated?

The roadblock locations selected by the Buffalo Police Department were high-priority problem areas. Effects were measured at the street segments and intersections with the roadblocks and those immediately leading up to the roadblocks where the intervention had high visibility. In total, 328 street units that had roadblocks or were near them were compared with 328 control street units matched (via propensity scores) on crime, accidents, and demographic variables. Researchers examined the roadblocks’ effects on Uniform Crime Reports Part 1 violent and nonviolent crimes, calls for service, and vehicle accidents using approximately three years of pre-intervention and one-and-a-half years of post-intervention data. The research team compared trends at the intervention locations to those at control locations. Some analyses examined effects for the full 1+ years following the roadblocks, while others focused on effects 2-4 weeks following the roadblocks.

What were the key findings?

Findings from the study were mixed and inconclusive. Depending on the statistical methods and follow-up period used, crime (particularly violence) appeared to rise after the intervention in some analyses and decline in others. Similarly, estimated impacts on accidents were inconsistent across analyses.

What were the implications for law enforcement?

The study results, taken in the context of the larger body of research on ALPRs, suggest that more robust crime and disorder prevention outcomes may be possible using ALPR roadblocks if modified to focus on a smaller number of locations with an increased number of repeated roadblock deployments to each location. The authors also caution that given the modest crime reduction findings, the benefits of this strategy may not outweigh citizen concerns regarding the presence of these roadblock deployments in their neighborhoods.

Where can I find more information about this intervention, similar types of intervention, or related studies?