RESEARCH TRIANGLE PARK, NC – RTI International developed and released the RTI Statistical Traffic Analysis Report (RTI-STAR), a free online tool that allows police departments to identify racial bias in traffic stops conducted by their agency.
"When it comes to racial bias, any bias is too much," said Travis Taniguchi, Ph.D., a research criminologist at RTI. "Agencies have a vested interest in making sure their officers aren't conducting traffic stops in a racially biased manner. This requires that agencies have access to tools that allow them to check for bias. RTI-STAR helps agencies look critically at their own operations and evaluate the possibility of bias in traffic enforcement."
RTI funded the development of RTI-STAR as a service to the community and to facilitate the growing desire of law enforcement agencies to critically analyze their operations.
The tool uses the veil of darkness approach, which is a rigorous methodology that is based on the assumption that police officers are less able to observe the race of a driver when it is dark outside.
Using this method, RTI-STAR assesses racial disproportionality by comparing the race of drivers stopped during daylight to the race of those stopped during darkness. The tool examines traffic stops during the intertwilight period roughly between 5:30 p.m. and 9 p.m., during which it is light at some times of the year but dark during other times. If minority drivers are more likely to be stopped during daylight, compared to darkness, there is evidence of racial bias.
To use RTI-STAR, the user inputs their city and uploads their traffic stop data. The application calculates civil twilight, whether the event happened during daylight or darkness, and whether the racial composition of the drivers stopped was conditional upon lighting.
The tool is available to use by anyone who has access to traffic data. In many states those data are publicly available.
"Many law enforcement agencies collect these kinds of data, but often don't have the time or expertise to analyze them in a scientifically rigorous manner," Taniguchi said. "RTI-STAR makes it easy for agencies to determine if there is evidence of racial bias in their traffic enforcement activity."