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In 2013, the CPD conducted 100,676 traffic stops. See Exh. 1. The American Civil Liberties Union of Illinois analyzed the underlying IDOT data regarding these stops. We found significant racial disparities in traffic stops, both City-wide and in the police districts that contain the fewest minority residents. We also found significant racial disparities in four kinds of searches conducted during these traffic stops. Specifically, we found:

• City-wide. The rate of black drivers in the stops (46%) is far higher than the rate of black residents in the city population (32%). See Exh. 2. White and Hispanic drivers are stopped at rates lower than their population.

• In higher-white police districts. In the five police districts where whites are a majority of the resident population, minority motorists are significantly over-stopped. As expressed in ratios of stop rates to population rates, black motorists are over-stopped by ratios ranging from 1.7 to 7.5, and Hispanic motorists are over-stopped by ratios ranging from 1.1 to 2.3. For example, in District #18 (Near North), where the resident population is 76% white, blacks are 9% of the residents and 19% of the traffic stops (yielding an over-stop ratio of 2.1), and Hispanics are 5% of the population and 11% of the stops (yielding an over-stop ratio of 2.3). See Exh. 2. [1]

• Searches of vehicles by consent (1,390 times). CPD was over four times more likely to search black and Hispanic motorists, compared to white motorists (4.74 and 4.09 times). See Exh. 3. CPD was about twice as likely to find contraband when they searched white motorists, compared to black and Hispanic motorists (2.1 and 1.86 times). See Exh. 4. (The points in this paragraph were part of the ACLU’s August 2014 published report about consent searches of cars throughout Illinois.)

• Searches of vehicles by non-consent (2,421 times). CPD was far more likely to search black and Hispanic motorists compared to white motorists (3.42 and 4.82 times). See Exh. 6. CPD was far more likely to find contraband when they searched white motorists, compared to black and Hispanic motorists (1.76 and 1.51 times). See Exh. 7.

• Searches of drivers by consent (1,597 times). CPD was far more likely to search black and Hispanic drivers compared to white motorists (4.9 and 4.46 times). See Exh. 8. White motorists were slightly less likely than black motorists to be caught with contraband (0.94 times), and were more likely than Hispanic motorists to be caught with contraband (1.34). See Exh. 9.

• Searches of drivers by non-consent (2,668 times). CPD was far more likely to search black and Hispanic motorists compared to white motorists (3.72 and 5.22 times). See Exh. 10. CPD was far more likely to find contraband when they searched white motorists, compared to black and Hispanic motorists (1.65 and 2.70 times). See Exh. 11.

For all analysis of traffic stop rates depending upon the race of the driver, city-wide and by district, see Exh. 2.
A. City-wide
On a City-wide basis, black drivers are over-stopped:

B. The nine whitest districts
In all nine of the whitest districts (listed below in descending order of whiteness), black drivers are notably over-stopped. The column on the far right (% black stops / % black residents) states the degree of over-stopping, e.g., “2.06” for Near North means that the black stop rate is a little more than double the black population rate. Note that the rate of over-stopping black motorists in these whiter districts (1.52 to 7.46) is substantially higher than the already high rate of over-stopping black motorists on a city-wide basis (1.42). Specifically:

Likewise, Hispanics motorists are over-stopped in all five majority white districts, at rates ranging from 1.1 to 2.3.

A. Overview
In 2013, the CPD reported conducting 9,643 searches during traffic stops. For each search, the CPD data identify what was searched (the car, the driver, or the passenger), and the basis for the search (consent or some other basis). The following chart summarizes the number of searches, by type.

In all four kinds of searches analyzed in this report, black and Hispanic motorists were significantly more likely to be searched, and white motorists were significantly more likely than Hispanic motorists to be caught with contraband. In three of four kinds of searches, white motorists were significantly more likely than black motorists to be caught with contraband. In the one exception to this pattern (consent searches of drivers), black motorists were only 6% more likely than white motorists to be caught with contraband. This hit-rate pattern generally holds when the different types and amounts of contraband are disaggregated. [2]
B. ​Searches of cars by consent

CPD conducted 1,390 consent searches of vehicles in 2013. See Exh. 3. Other than the ISP, the CPD conducted more vehicle consent searches than any other police agency in Illinois. See IDOT 2013 report at p. 11.

Minority motorists were far more likely to be searched. Specifically, black motorists were 4.74 times more likely than white motorists to be searched, and Hispanic motorists were 4.09 times more likely. The pattern for 2013 mirrors earlier years: from 2004 to 2012, minority motorists were three to seven times more likely than white motorists to be searched. See Exh. 3.

White motorists were far more likely to be caught with contraband, taking all forms of contraband as a whole. Specifically, white motorists were 2.1 times more likely than black motorists, and 1.86 times more likely than Hispanic motorists, to be caught with contraband. The hit rates were 12% for black motorists, 13% for Hispanic motorists, and 24% for white motorists. From 2007 to 2012, white drivers also were more likely than minority drivers to be caught with contraband, with just one exception (in 2008 the white/black hit rate disparity was 0.98). See Exh. 4.

When the 179 busts are disaggregated by type and quantity of contraband, the higher white hit rate generally holds. For example, white motorists were more likely to be caught with drugs, including all specific quantities of drugs up to 100 grams. There are a few exceptions to this norm: the only drug bust larger than 100 grams (type and precise amount unreported) involved a black motorist; all seven weapon busts (types unreported) involved black or Hispanic motorists; the only stolen property bust involved a black motorist; and all but one of the 32 alcohol busts involved black or Hispanic motorists. See Exh. 5. ​

C. ​Searches of cars by non-consent
CPD conducted 2,421 non-consent searches of vehicles in 2013. Minority motorists were far more likely to be searched. Specifically, black motorists were 3.42 times more likely than white motorists to be searched, and Hispanic motorists were 4.82 times more likely. The search rates were 3.9% for Hispanic motorists, 2.8% for black motorists, and 0.8% for white motorists. See Exh. 6.

White motorists were far more likely to be caught with contraband, taking all forms of contraband as a whole. Specifically, white motorists were 1.76 times more likely than black motorists, and 1.51 times more likely than Hispanic motorists, to be caught with contraband. The hit rates were 17% for black motorists, 20% for Hispanic motorists, and 30% for white motorists. See Exh. 7.

When the 473 busts are disaggregated, the higher white hit rate generally holds. For example, white motorists were more likely than black and Hispanic motorists to be caught with drugs, more than 100 grams of drugs, and weapons. There are a few exceptions to this norm: all four of the drug busts of 51 to 100 grams involved black or Hispanic motorists; the only stolen property bust involved a black motorist; and Hispanic motorists were more likely than white motorists to be caught with alcohol. Id.

D. Searches of drivers by consent
CPD searched 1,597 drivers by consent in 2013. CPD was far more likely to search black and Hispanic motorists compared to white motorists (4.9 and 4.46 times). See Exh. 8.
The hit rates were 4.61% for black motorists, 3.25% for Hispanic motorists, and 4.35% for white motorists. Thus, white motorists were slightly less likely than black motorists to be caught with contraband (0.94 times), and more likely than Hispanic motorists to be caught with contraband (1.34). See Exh. 9. For context, please note: whites were more likely that Hispanics to have contraband in all four types of searches analyzed in this report; whites were more likely to then blacks to have contraband in three of the four types of searches; in consent searches of drivers, blacks were only 6% more likely than whites to have contraband; and when whites were more likely than minorities to have contraband, the differentials were much higher (respectively 34%, 51%, 65%, 76%, 86%, 210%, and 270%).

When the 39 busts are disaggregated, whites are more likely than blacks or Hispanics to have drugs. On the other hand, minorities but not whites were caught a very small number of times with 11 to 50 grams of drugs (3 times), 51 to 100 grams (2 times), paraphernalia (3 times), alcohol (1 time), weapons (1 time), stolen property (1 time), or other contraband (1 time). See Exh. 9. ​

E. ​Searches of drivers by non-consent
CPD searched 2,668 drivers by means other than consent in 2013. CPD was far more likely to search black and Hispanic motorists compared to white motorists (3.72 and 5.22 times). See Exh. 10.
White motorists were far more likely to be caught with contraband, taking all forms of contraband as a whole. Specifically, white motorists were 1.65 times more likely than black motorists, and 2.70 times more likely than Hispanic motorists, to be caught with contraband. The hit rates were 6% for black motorists, 4% for Hispanic motorists, and 10% for white motorists. See Exh. 11.

When the 95 busts are disaggregated, the higher white hit rate generally holds. There are a few exceptions: black and/or Hispanic motorists, but not white motorists, were caught a few times with alcohol (4 times), weapons (7 times), stolen property (1 time), or other contraband (4 times). Id.

This report is only the most recent of many reports showing ongoing racial disparities in encounters between police and members of the general public in Illinois. To begin to remedy this serious problem, the ACLU of Illinois call for the following reforms:

1. Make permanent the Illinois Traffic Stop Statistical Study Act. All the traffic stop and search data in this report was collected pursuant to this critical law, which was sponsored in 2003 by then-State Senator Barack Obama. Unfortunately, this law is scheduled to expire in a few years.
2. Expand the Study Act to sidewalk stops. CPD sidewalk stop data indicates racial disparity in the use of that police tactic, too.
3. Abolish consent searches during routine traffic stops. They have a racially disparate impact, and in many cases are not truly consensual.
4. Require all police to wear and use body cameras during their encounters with civilians, subject to necessary privacy safeguards.
5. Require all police to issue a receipt (or other documentation) to all civilians they interact with, including during traffic stops, sidewalk stops, and consensual encounters. This receipt should state the officer’s name, the time and place of the encounter, and the reason for the encounter. Such receipts will facilitate any civilian complaints regarding the encounter.

[1] Please note that nearly 10% of all CPD traffic stops in 2013 (9,695 of 100,676) lack a reported district. See Exh. 2.
[2] Please note a few data and methodological points. The CPD data report very few searches in some districts; for example, District #1 (Central), with 3,875 traffic stops in 2013, reports only 12 searches. See Exh. 12. The CPD data do not identify passenger race, so this report does not analyze searches of passengers. The CPD data on contraband do not distinguish driver and passenger searches, so the driver search hit-rate analysis in this report does not include stops where both the driver and a passenger were searched.