A Quasi-Experimental Evaluation Using Roadblocks and Automatic License Plate Readers to Reduce Crime in Buffalo, NY

Abstract

Purpose: To evaluate the effectiveness of a hot spots policing strategy: using automated license plate readers at roadblocks.Methods: Different roadblock locations were chosen by the Buffalo Police Department every day over a two month period. We use propensity score matching to identify a set of control locations based on prior counts of crime and demographic factors before the intervention took place. We then evaluate the reductions in Part 1 crimes, calls for service, and traffic accidents at roadblock locations compared to control locations.Results: We find modest reductions in Part 1 violent crimes (10 over all roadblock locations and over the two months) using t-tests of mean differences. We find a 20% reduction in traffic accidents using fixed effects negative binomial regression models. Both results are sensitive to the model used though, and the fixed effects models predict increases in crimes due to the intervention.Conclusions: While the results are mixed, it provides some evidence that the intervention has potential to reduce crime. We suggest that the limited intervention at one time may be less effective than focusing on a location multiple times over an extended period.