As social justice advocates target police violence against people of color, traffic stops are under growing scrutiny. Here's everything you need to know: Why are traffic stops important? Scores of studies have shown the same pervasive pattern: Black people are more likely to be pulled over for traffic violations, and more likely to be searched when they're stopped. The most comprehensive study of the issue comes from Stanford University's Open Policing Project, which in 2020 found "persistent racial bias" in nearly 100 million police stops made by 21 state agencies and 35 municipal departments. Tellingly, the racial disparity dropped after sunset — when it's harder for an officer to see a driver's face. Black drivers were searched about twice as often as white drivers — even though they were less frequently found to be carrying contraband. "'Driving while Black' is very much a thing," says Kelsey Shoub, an assistant professor at the University of South Carolina and co-author of Suspect Citizens, a book analyzing 20 million traffic stops. "It appears to be more systemic than a few 'bad apple' officers engaged in racial profiling."