Traffic stops by Iowa City police show ‘steady or decreasing’ racial disproportionality

IOWA CITY — Traffic stops made by Iowa City police in the last two years show “steady or decreasing amounts of racial disproportionality,” according to a recent report, but people of color still are more likely to be arrested after the stops.

The report from CR Research Group LC, prepared by Christopher Barnum, analyzed racial disproportionality in traffic stops in the city and outcomes of these stops in 2019 and 2020.

The report found low levels of disproportionality in citations, but a higher level of disproportionality in arrests. People of color were arrested twice as often following a traffic stop.

“The disproportionality in arrests, however, does not appear to be trending higher over the last three years,” Barnum wrote. “And it is important to note that almost all arrests in recent years were made for nondiscretionary offenses, meaning the officer had little or no choice in deciding to make an arrest.”

Barnum and his team have reviewed traffic stop data in several other cities, which soon will include Cedar Rapids. The Cedar Rapids City Council budgeted $30,000 in its fiscal 2022 budget for a three-year analysis of traffic stop data and outcomes

The Iowa City Police Department has been collecting demographic data on traffic stops since 1999, Chief Dustin Liston wrote in a memo. The department hired Barnum in 2006 to analyze trends. He is a professor at St. Ambrose University in Davenport and also director of the university’s master’s program in criminal justice.

Barnum and his team divide Iowa City into 1-square-mile zones. They then use roadside observations and census data to determine the expected number of stops in these areas.

There were 14,111 total stops in 2019 and 6,497 in 2020, according to the report. Iowa City police made 7,614 fewer stops in 2020 likely due to the COVID-19 pandemic, Barnum wrote.

Officers made more stops at night than during the day, the report found. Stops after 7 p.m. were considered nighttime stops.

In 2019, 71 percent of stops were made at night. In 2020, just over half — 57 percent — of stops were at night.

A plurality of stops occurred in the downtown area, followed by the Broadway-Wetherby area and surrounding zones, according to the report. About 40 percent of traffic stops were in the downtown area both years. A map of the observation zones can be found within the report, which is available on the city’s website.

Citywide, in 2019, the proportion of traffic stops of people of color was 9 percent higher than the benchmark. In 2020, it was 7 percent higher than what was expected.

Levels of disproportionality were higher at night than during the day for both years.

The report also analyzed disproportionality in outcome after someone is stopped, such as citations and arrests.

People of color were arrested twice as often following a traffic stop but received citations at about the same rate as white drivers, according to the data.

Barnum noted “a large majority of the arrests made in both 2020 and 2019 were for nondiscretionary charges,” meaning officers had “very little or no choice in deciding whether or not to make an arrest” due to state law or departmental policy.

In 2019 and 2020, respectively, 93 and 96 percent of arrests were nondiscretionary. Examples of such required arrests are bench warrants, driving while barred and drunken driving.

Recommendations

Barnum concluded the report with recommendations. He suggested police department include exact coordinates of stops in the data sets, as well as additional information about the vehicle occupants, such as if they were asked to step out of the vehicle.

In his memo, Liston wrote how the department currently is capturing more precise location information and will explore getting data on passengers at traffic stops.

Barnum noted how “a sizable majority” of the stops were for offensives that weren’t issued a traffic citation.

“Police managers should assess and evaluate the reasonableness of the practice of stopping large numbers of vehicles for offenses that officers deem deserving of only a warning,” Barnum wrote.

Liston wrote how the department “has always taken an education-first approach to traffic enforcement.”

“Efforts to address disproportionality in traffic stops are continuous and ongoing,” Liston said.

Comments: (319) 339-3155; izabela.zaluska@thegazette.com