New study of 20 million traffic stops in NC finds stark racial disparities

Professors at the University of North Carolina, Chapel Hill and the University of Texas studied North Carolina traffic stop data back to 2002 and found stark racial disparity in policing at stops. City Lab first reported on highlights of the 20 million stops analyzed by researchers.

This research comes after N.C. passed legislation that adds instruction on how to behave in a traffic stop to driver’s education curriculum.

There are about one to 1.6 million traffic stops each year in N.C. and about 10 million people living in the state. This means North Carolinians should have a 10 to 15 percent chance of being pulled over each year.

However, when this data is broken down by race, odds of being pulled over were significantly higher for black drivers when compared to white and latinx drivers. On average, black drivers were 60 to 70 percent more likely to have been stopped when controlling for population density. This racial bias is most likely to be underestimating the disparity when taking access and ownership to cars, which is greater in white populations, into account. 

That is why researchers gave the most attention to data around who gets searched after a traffic stop as a more clear indicator of racial disparities. When researchers controlled for reason for stop, time of day, day of week, month of year, and specific law enforcement agency they found that young people, men, and people of color are much more likely to be searched after a traffic stop 

Data around the outcome of searches and stops point to another key finding about racial biases in traffic stops. In the case of white motorists, more traffic tickets are issued after stops because there is concrete evidence of an offense, but stops involving motorists of color often involve unclear for the stop, meaning the person may not end up being penalized through tickets.

There are two reasons for traffic stops, a violation of the law or the desire by law enforcement to investigate a person. Researchers found that people of color are much more likely to be stopped for unclear reasons based on the data around outcomes of traffic stops and searches.

Researchers point out that young men of color get pulled over on a very routine basis, and it is not “trivial.” Searches can be humiliating, take a lot of time, and usually “come up dry.” Similar to the outcome data, law enforcement is less likely to find contraband on black drivers searched than on white drivers. Again, suspicion plays a role in the decision to search black drivers while clear evidence is needed to search white drivers.

The best predictor of low racial disparity in traffic stops in across N.C. municipalities is black representation on the city council. Whereas, when researchers looked at what they called a more typical N.C. community with low levels of black political power they saw the highest rates of racial disparity in traffic stops. Elections matter.

Finally, researchers debunked the “bad apple” law enforcement officer theory. When they isolated “bad apple” officers (officers with a very high rate of racial disparity in stops and searches) they found that this could not account for the disparities observed. The problem is institutionalized and culturally normative. 

Teaching teenagers how to behave when they are stopped by law enforcement clearly does not solve the larger problem of systemic racism.