Black drivers in Chicago are more likely to be stopped by police than issued tickets by traffic cameras, highlighting the role of racial bias in traffic stops, according to a new study.
The findings, published this month in the Proceedings of the National Academy of Sciences, follow years of scrutiny of racial disparities in Chicago traffic stops.
They also come amid renewed debate about the use of the stops, as outgoing Cook County State’s Attorney Kim Foxx unveiled a controversial proposal to decline to prosecute possession cases when guns or drugs are found during traffic stops initiated for reasons like expired registration or a broken light. Officials also recently moved to add oversight of traffic stops to a federal consent decree guiding Chicago Police Department reform.
In the latest study, researchers from the University of Illinois Chicago, Cornell University, Rutgers University and the University of Sydney in Australia analyzed GPS data from cellphones and 2019 data on traffic stops and speed camera tickets. They determined the racial makeup of drivers on the road, and compared that with the demographics of the people stopped or ticketed.
They found that on a street where half of drivers were white, the probability of a white driver getting a traffic camera ticket was just under 50%, while white drivers made up, on average, fewer than 20% of police stops.
On a street where half of drivers were Black, the probability of a Black driver getting a camera ticket was 54%. But Black drivers made up about 70% of police stops.
Comparing automated camera data to stops initiated by police sheds light in a clear way on the human role of the stops, said Nebiyou Tilahun, one of the study’s authors and an urban planning and policy professor at UIC.
“It specifically shows bias,” he said.
Asked about the study, CPD reiterated a statement it previously issued in light of the recent consent decree development, saying “Superintendent (Larry) Snelling is committed to ensuring traffic stops are being used effectively.” The department agreed to include the stops in the consent decree, and had already been reviewing use of the stops and is training officers, police said.
Traffic stops were down by about 80,500 year-to-date, the Police Department said Thursday, and felony arrests had increased by about 500. The department routinely initiates more than a half-million traffic stops each year.
Sometimes caught up in those stops is a 42-year-old insurance broker. The man, who is Black, said he has frequently been pulled over and asked that his name be withheld to talk about interactions with police.
One traffic stop stood out to him. It was near the University of Chicago one evening some nine years ago when his son, then around 5, was in the car. He asked an officer why he was pulled over and asked to talk with a supervisor, but was never told why he was stopped, he said.
He recalled how his heart thumped in his chest with worry as the officers held his license and registration.
“I get it. Cops have a job to do, whatever that job is,” he said. “That’s one aspect. But the other aspect is: Listen, man. I’m a citizen. I don’t want to do anything other than make it home right now.”
Chicago has for years grappled with concerns about racial disparities in traffic stops. The number of traffic stops began rising dramatically in 2016, at the same time stops of pedestrians plummeted after a new state law and an agreement between the ACLU and the Police Department required officers to more thoroughly document and justify the pedestrian encounters to ease concerns about racial profiling and constitutional violations.
The debate over traffic stop policy has continued more recently. The consent decree development concerning how traffic stops are monitored followed the fatal shooting of Dexter Reed in March during a traffic stop. Body-worn camera footage showed Reed, purportedly pulled over for not wearing a seat belt, shooting an officer in the wrist before four other tactical officers opened fire, killing the 26-year-old man.
Foxx said she was grateful Snelling agreed to include traffic stops in the consent decree. But she described her proposal declining certain charges from certain stops as another response to “racism baked into the system.”
“If not this, what should we be doing?” she asked. “Where is the urgency from all of our stakeholders to address the repeated findings of systemic racism in these studies? It is not enough to simply say what we can’t do. I’m looking for someone to tell me what we can.”
The concept has stirred controversy. Foxx is set to leave office in the coming months, but said she wanted to move along the process to try to address the issue, though the next state’s attorney could have the ability to keep or scrap the policy.
In an April report, advocacy organization Impact for Equity found Chicago police conducted more traffic stops in 2023 than the year before, and the stops were largely for improper registration and headlight, taillight and license plate offenses, considered minor violations.
Nearly 4% of stops led to a citation and 2% led to an arrest, the report found. And Black and Latino drivers were disproportionately stopped and arrested, according to the report.
Impact for Equity and the Free2Move Coalition, a group focused on racial equity in traffic safety in Chicago, called for reducing pretextual traffic stops, or a stop for a minor violation like expired registration used as an excuse to search for evidence of an unrelated crime.
“It’s not resulting in any sort of public safety gains,” said Amy Thompson, staff counsel for Impact for Equity’s criminal legal system section. “And I think what we see is that really degrades trust between communities and law enforcement, when they perceive that they are just a target for law enforcement and not a true partner.”
Another layer to the traffic enforcement issue is differences in the level of investment across Chicago communities, Thompson said. It can be easier to speed down streets in neighborhoods primarily of color, which often don’t get the same safety measures meant to slow traffic that are put in place in other city neighborhoods. And neighborhoods that have been disinvested in for years have fewer businesses, limiting foot traffic on streets and making it easier to speed, she said.
The latest study, comparing enforcement to who is using the road and looking at both traffic stops and camera tickets, builds on Impact for Equity’s findings, said Wenfei Xu, another of the study’s authors and a professor at Cornell.
“If the aim is to arrest, (a traffic stop) doesn’t seem very effective in terms of how we’re spending taxpayer money,” she said, citing the low arrest rate found by Impact for Equity.
The city’s use of automated ticketing has drawn its own concerns from critics, and several investigations have examined the impact on low-income violators and households in majority Black and Hispanic areas. A 2022 ProPublica investigation found that households in majority Black and Hispanic ZIP codes in Chicago “received tickets at around twice the rate of those in white areas,” despite cameras being roughly evenly distributed across the city.
The traffic stop study’s authors said automated cameras provided a more race-neutral comparison point. The study refutes arguments that perhaps Black drivers speed more than other drivers, pointing instead to human bias, said Michael Smart, a study author and urban planning and policy professor at Rutgers.
“(Bias is) not just a police issue,” he said, “But it’s especially acute among police because of the powers that police are given.”
A 35-year-old South Shore resident, who requested his name not be used, said he has experienced that bias firsthand.
The man, who is Black, still recalls his first traffic stop when he was a junior at Mount Carmel High School, driving the red 1992 Mustang he and his dad had fixed up.
A string of other traffic stops followed, like the embarrassing one his then-girlfriend’s family witnessed while he was waiting to pick her up from a family gathering downtown, he said. Or the disconcerting one, years later when he was driving a black 2005 Mustang, when he was cut off and boxed in by several police cars after dropping his girlfriend off after dinner.
The man, who loves American muscle cars, now drives a Honda Civic, reserving the Mustang for special cruises in the summer. After being pulled over so many times in the Mustang he was frustrated and wanted to draw less attention to himself, he said.
Even so, he said he was pulled over three times in two years in the Civic, though at least one was not by Chicago police.
“I’m always trying to go home,” he said. “My focus is going home.”
This story has been updated to correct a reference to the next Cook County state’s attorney.
