Summary of Traffic Stops Statistics

Figure 2 shows the total number of traffic stops by race and gender from 2002-2020. For example, in 2002, roughly 28% of total traffic stops were of white males, roughly 27% of stops were of black males, roughly 17% were of black females, and roughly 15% were of white females. White male driver’s share of those stopped decreased over the timeframe, while both black males and females slightly increased as a proportion of total stops.

Figure 3 shows the percentage of traffic stops that are considered safety-related for each respective race and gender grouping, from 2002-2020. Safety-related spots are composed of stops due to speeding, stop sign violations, DWI, and unsafe movement. Stops for violations other than this are classified as non-safety related. These are composed of non-moving violations such as equipment violations and expired tags. For this reason, non-safety-related stops can be considered to be used as informal criminal investigations. Each race and gender grouping follows a similar trend from 2002-2020. White females and white males have a similar percentage of safety-related stops throughout the time period. Black drivers consistently had a lower percentage of their stops classified as safety-related as compared to white drivers.

Figure 4 shows the percent of traffic stops that result in a search for each respective race and gender grouping, from 2002-2020. The Figure indicates that most traffic stops do not result in a search. For all categories except black males, drivers were searched at less than a 10% rate across the time period. Black males were typically searched at higher rates, ranging from 10 to 22% across the time period. This is roughly two to three times as often as the second most searched group, white males, who were searched in 4 to 8% of stops. White and black female drivers experienced similar levels of search rates over the time period, with both groups being searched at a lower rate than white and black males.

Figure 5 shows the percent of traffic stops that result in an arrest for each respective race and gender grouping, from 2002-2020. Across the board, arrest rates are consistently very low, at under 8% for all categories across the time period. Black males are arrested at the highest rate, and white males are arrested at roughly half the rate. Females, regardless of race, are arrested at lower rates than male. Black males have a certain degree of variance from year to year in their arrest rates, but for all other categories arrest rates have stayed relatively steady across the time period. From 2002-2004 and 2006, arrest data is missing and therefore is not displayed in the Figure.

Figure 6 shows the percent of searches that result in the finding of contraband for each respective race and gender grouping, from 2002-2020. Across the time period, there is a clear upward trend in contraband hits per search. In 2002, the rate of contraband discovery was between 20% and 30% for all categories, and this steadily increased until 2020, in which contraband was discovered between 55% and 70% of searches. The percent of searches leading to contraband is extremely similar for each of the race and gender categories, increasing at an very similar rate across the time period.

Figure 7 shows the percent of searches that resulted in the discovery of contraband and an arrest for each respective race and gender grouping, from 2002-2020. Note that in many instances, contraband hits do not lead to arrest due to it being found in small amounts. As seen in the Figure, the rate of contraband hit and arrest per search has steadily increased across the time period for all categories. Black males, white males, and white females all have maintained similar rates, increasing from a 10-15% rate of contraband and arrest per search to a rate of roughly 30%. The rate for black females has also increased over the time period, but to a lesser degree, resulting in a significant gap between their outcomes and the rest of the gender/race categories by 2020, with only 20% of their searches resulting in contraband and arrest. From 2002-2004 and 2006, arrest data is missing and therefore is not displayed in the Figure.

Figure 8 shows the percent of stops that resulted in the discovery of contraband and an arrest for each respective race and gender grouping, from 2002-2020. The rates are very low for each category. White males, white females, and black females all have rates of less than 1.5% across the time period with very little variation. The rates for black males have increased slightly, from 2% of stops in 2005 to 4% of stops in 2020 resulting in contraband and arrest. Overall, for all race and gender categories, traffic stops are overwhelmingly unlikely to result in contraband and arrest. From 2002-2004 and 2006, arrest data is missing and therefore is not displayed in the Figure.

Figure 9 shows the rate of a contraband hit and an arrest for consent searches of each respective race and gender grouping, from 2002-2020. Consent searches are warrantless searches in which the stopped person gives permission (either verbal or written, varying by department) to the officer to search their vehicle. The percent of consent searches resulting in contraband and arrest have not followed a clear trend across the time period. White male drivers typically had the highest percent of their consent searches result in contraband and arrest, with exceptions in 2012 and 2016. The percentage for black males and females ranged from 2-10% across the time period, with no steady periods of increase or decrease. From 2002-2004 and 2006, arrest data is missing and therefore is not displayed in the Figure.

Figure 10 shows the rate of discovery of contraband and an arrest for consent searches of each respective race and gender grouping, from 2002-2020. The Figure does not include white females because there is insufficient data. A probable cause search is a warrantless search of the vehicle which can be conducted if the officer reasonably believes that the person has committed a crime. The searched person does not have to consent to a probable cause search for it to be conducted. The Figure shows that across the time period, a majority of probable cause searches do not result in contraband or arrest. For white males, the rate of a contraband hit and arrest from a probable cause search ranged from roughly 15-40%. For black males, the rate ranged from 15-30%. Probable cause searches of black females result in contraband and arrest at a lower rate. From 2002-2004 and 2006, arrest data is missing and therefore is not displayed in the Figure.

Figure 11 shows the percentage of contraband hits that result in an arrest for each respective race and gender grouping, from 2002-2020. The Figure does not include white females because there is insufficient data. The Figure indicates that a majority of contraband hits do not result in arrests, with the sole exception of white males in 2013. This is explained by the fact that the contraband is often found in very small amounts. Black and white males are arrested at similar rates across the time period, ranging from 30 to 50%, with significant variation on a year to year basis. Black females are arrested in a lower percentage of contraband hits, and this rate of arrests to contraband hits has decreased from 2002 to 2020, from around 35% to 25%. From 2002-2004 and 2006, arrest data is missing and therefore is not displayed in the Figure.

Figure 12 compares the search rate and arrest rate of black males and white males from 2002-2020. The search rate ratio is the search rate of black males divided by the search rate of white males, while the arrest rate ratio is the arrest rate of black males divided by the arrest rate of white males. A search rate ratio of 1.0 would indicate that black and white males are both searched in an equal percentage of their respective traffic stops. This similarly applies for the arrest rate ratios. Across the time period, the search rate ratio is consistently at or above roughly 2.5, peaking at greater than 4.0 in 2017 and 2019. This means that black males are searched much more frequently than white males. The arrest rate ratio is on average lower than the search rate ratio of the same year, with the sole exception being 2020. This means that black males are arrested at a greater rate than white males, but not to the degree that they are disproportionately searched. From 2002-2004 and 2006, arrest data is missing and therefore there is no arrest rate ratio for these years.

Figure 13 compares the search rate and arrest rate of black females and white females from 2002-2020. The search rate ratio is the search rate of black females divided by the search rate of white females, while the arrest rate ratio is the arrest rate of black females divided by the arrest rate of white females. A search rate ratio of 1.0 would indicate that black and white females are both searched in an equal percentage of their respective traffic stops. Across the time period, the search rate ratio ranges from 0.8 to 2.0. The arrest rate ratio is typically lower than the search rate ratio for each given year, with an exception in 2005. From 2002-2004 and 2006, arrest data is missing and therefore there is no arrest rate ratio for these years.

Figure 14 displays the number of traffic stops, the percent of safety related stops, the percentage of drivers receiving a citation, the percentage of drivers searched, and the percentage of drivers arrested across the hours of the week. The Figure indicates that there is not much variation between the days of the week in regard to these measures, and instead shows that the variation is seen within the hours of the day. There are a few noticeable trends throughout the week, however. Stops occur most frequently on Wednesday, Thursday, and Friday nights relative to other days at the same time. Search and arrest rates are slightly higher in the very early morning (directly after midnight) on Saturdays and Sundays.

Figure 15 displays the number of traffic stops, the percent of safety related stops, and the percent of drivers searched, given a citation, and arrested by hour of day. There are a number of clear trends indicated in the Figure. The frequency of a traffic stop is lowest in the early hours of the morning, from around 3AM to 6AM. The number of traffic stops increases until 8AM, at which the frequency is similar until around 6PM. From 6PM to 9PM stops increase, and until midnight stops occur at a higher rate. At midnight, the frequency of stops begins to drop.

The percentages of drivers searched and arrested both have a similar trend across the time of day. Drivers are both searched and arrested at the highest rate in the few hours after midnight, and then these rates of search and arrest decrease dramatically until 6AM. After 6AM, the rate of both search and arrest is at extremely low percentages, and both slowly increase throughout the daytime and into the late night time hours.

The percentage of drivers receiving a citation follows an opposite trend of search and arrest rates. The rate of citations given is at its lowest from 9PM to 4AM, and then in the following hours steadily increases. The rate is significantly higher during daytime hours as compared to nighttime hours.

The percent of safety-related stops varies throughout the day, reaching its highest point at 7AM and then steadily decreasing for the rest of the day until a minimum is reached at 10PM. From 10PM to 7AM the rate increases, with dramatic increases in the percentage of safety-related stops indicated from 3AM to 5AM.

Figure 16 displays the share of overall stops represented by the respective race and gender categories by hour of day. The Figure indicates that black males are more likely to be stopped during the nighttime hours directly before and after midnight than they are to be stopped during the daytime. At 3AM, black males reach a high of 43% of those that are pulled over, and by 7AM their share of stops decreases to 21%, and stays at a lower proportion of stops throughout the daytime hours. White males, in contrast, make up a relatively consistent share of the overall traffic stops throughout the day, at around 20%. There are no significant variations during the daytime or nighttime. Black females make up a relatively consistent share of traffic stops throughout the day, with similar levels to white males. White females consistently represent the lowest percentage of stops across the period. They see a slight uptick in their proportion of stops during the daytime hours.

Figure 17 displays the percentage of stops that are for safety-related purposes for each race and gender category, by hour of the day. Safety-related purposes refer to traffic stops that are meant to prevent moving violations, and effectively keep the road safe. Stops that are not safety-related are often used for investigatory purposes, in which case the officer is generally seeking to conduct an informal criminal investigation of the driver. As evidenced in the Figure, black drivers are much less likely to be stopped for safety-related purposes than white drivers throughout the course of the day. In turn, this means that black drivers are more likely to be subjected to investigative stops that are not for moving violations. These stops are most common during the nighttime hours, when the percentage of safety-related stops is lowest. At any given hour of the day, black drivers are significantly more likely to be stopped for a non safety-related purpose than white drivers.

Figure 18 displays the percentage of traffic stops which result in a search for each race and gender category, by hour of the day. Black males are searched at the highest rate regardless of time of day, but the time of day does significantly influence the rate at which they are searched. Approaching and during the nighttime hours before and after midnight, from approximately 5PM to 5AM, black males are most likely to be searched during a traffic stop, and this search rate decreases during the daytime hours. This pattern applies for all of the gender and race categories. During daytime hours, however, black males are still significantly more likely to be searched than other race and gender categories. Throughout the entire day, white males are searched at a lower rate than black males, and females, regardless of race, are searched at a lower rate than males. The Figure also indicates that a majority of stops do not result in a search regardless of race and gender category or time of day.

Figure 19 displays the percentage of traffic stops which result in an arrest for each race and gender category, by hour of the day. For all categories, drivers are more likely to be arrested during nighttime hours, specifically the hours directly after midnight. Stops are most likely to result in an arrest from 2AM to 4AM. All race and gender categories have similar rates of arrest during these hours directly following midnight, except for black females. However, black males are more likely to be arrested than all other drivers from 4AM until 11PM, which constitutes a large majority of the day. The Figure also indicates that a large majority of stops do not result in an arrest regardless of race and gender category or time of day.

Figure 20 displays the distribution of number of stops by officer across the 2002-2020 time period. All officers displayed have over 100 traffic stops. 1,588 of the 2,132 officers included in the data have less than 1000 traffic stops.

Figure 21 displays the percentage of stopped drivers that are black for individual officers, from 2002-2020. The distribution includes officers with greater than 100 traffic stops. For the median officer, 57.1% of stops are of black drivers, while black people only make up 33% of the population in the city. This means that a majority of officers are stopping black drivers at a rate disproportionate to their share of the population. This disparity between stop behavior and population data is often greater, with black drivers composing more than 75% of stops for a significant portion of officers. At the far right, the Figure shows that there are 353 officers whose mix of drivers stopped is more than 80% black.

Figure 22 displays the search rates of individual officers for the given race and gender category. The criteria for an officer’s inclusion is 100 or more traffic stops, as well as at least 50 stops of the specified race and gender category, from 2002-2020. In the first graph, the median officer has a search rate of 8.55%, meaning that black male drivers are searched in 8.55% of traffic stops. Many officers have search rates that are higher than this median value, meaning that searches occur more often for certain officers in traffic stops involving black males. For white male drivers, the median officer has a search rate of 2.88%. This indicates that the median officer in Charlotte is searching black males at a higher rate than they are searching white males.

Figure 23 displays the distribution of black-white male search rate ratios across the officers which meet the criteria. The criteria for an officer’s inclusion is 50 traffic stops of both white males and black males, from 2002-2020. The “Black-white male search rate ratio” can be interpreted as an officer’s search rate of black male drivers divided by their search rate of white male drivers. An racially equitable outcome would therefore be 1, meaning that black and white male drivers are searched in an equal percentage of traffic stops. The median officer instead has a search rate ratio of 1.86, meaning that the median officer searches black male drivers at a higher rate than white male drivers. A significant number of officers have search-rate ratios that are much higher than the median, with some searching black male drivers at 5 or more times the rate of white male drivers.

Figure 24 presents the hit rates and search rates of individual officers who meet the criteria. As evidenced by the low correlation, there is great variability in both the propensity of individual officers to search drivers and their success in finding contraband. One might expect that when officers have a high search rate but a low hit rate, that their supervisors would advise them to adjust their search rate in order to avoid so many fruitless searches. Similarly, for officers with low search rates but high hit rates, one might expect supervisors to instruct them to conduct more searches because they are being too cautious. Such a learning process would generate relative consistent hit rates; where officers are too high, they would be advised to do more searches, and where too low, to conduct fewer. The Figure shows clearly that this is not happening. Search and hit rates range from low to high, with a very low correlation between the two. Certain officers search drivers at extremely high rates but have very low hit rates, meaning that their threshold of suspicion is likely too low. Other officers search at a much lower rate and have very high hit rates, showing that their threshold of suspicion may be too high. Overall, the Figure shows that officers are not gravitating towards a single common range of hit rates. This suggests that the departments across North Carolina do not seem to hold their officers to a common standard of search rate success. Rather, each officer decides for him or herself how aggressive to be in searching, with virtually no guarantee that more searches will lead to lower hit rates, or that fewer searches will be targeted on those most likely to have contraband.