Testing the racial profiling hypothesis for seemingly disparate traffic stops on the New Jersey turnpike

This paper describes two studies designed to produce benchmark values with which to compare police stop data in an effort to assess racial profiling. Racial profiling is often measured by comparing the racial and ethnic distribution from police stop rates to race and ethnicity data derived from regional census counts. However, benchmarks may be more appropriate that are based on (1) the population of drivers or (2) the population of traffic violators. This research surveyed drivers on the New Jersey Turnpike and produced benchmark distributions reflecting these two populations. Benchmark values then were compared to police stops collected from State Troopers patrolling the Turnpike. The results revealed that the racial make-up of speeders differed from that of nonspeeding drivers and closely approximated the racial composition of police stops. Specifically, the proportion of speeding drivers who were identified as Black mirrored the proportion of Black drivers stopped by police. This finding may explain the differences found between police stop rates and regional census data that are often interpreted as evidence of racial profiling. Interpretation and limitations of the results are discussed.