U.S. Department of Justice

Office of Justice Programs

Bureau of Justice Statistics

Special Report SEPTEMBER 2013 NCJ 242937

I

n 2011, over 62.9 million U.S. residents age 16 or older, 

or 26% of the population, had one or more contacts with 

police during the prior 12 months (figure 1). For about 

half (49%) of persons experiencing contact with police, the 

most recent contact was involuntary or police-initiated. In 

2011, 86% of persons involved in traffic stops during their 

most recent contact with police and 66% of persons involved 

in street stops (i.e., stopped in public but not in a moving 

vehicle) believed that the police both behaved properly and 

treated them with respect during the contact. A greater 

percentage of persons involved in street stops (25%) than 

those pulled over in traffic stops (10%) believed the police 

had not behaved properly. Regardless of the reason for the 

stop, less than 5% of persons who believed the police had not 

behaved properly filed a complaint. 

The data in this report were drawn from the Bureau 

of Justice Statistics’ (BJS) 2011 Police-Public Contact 

Survey (PPCS), a supplement to the National Crime 

Victimization Survey (NCVS), which collects information 

from a nationally representative sample of persons in U.S. 

households. The PPCS collects information on contact with 

police during a 12-month period. This report examines 

involuntary contacts with police, specifically those that 

occurred when the person was the driver of a motor vehicle 

(i.e., traffic stops) or when the person was stopped by the 

police while in a public place but not in a moving vehicle 

(i.e., street stops). It describes variations in perceptions of 

police behavior and police legitimacy during traffic and 

street stops. (For more information on how perceptions of 

police behavior and legitimacy were measured in this report, 

see survey questions on page 12.) All findings in this report 

are based on persons for whom the most recent contact in 

2011 was in a street stop or as the driver in a traffic stop. 

For information on voluntary contacts with police, see 

Requests for Police Assistance, 2011, NCJ 242938, BJS website, 

September 2013.

Lynn Langton, Ph.D., and Matthew Durose, BJS Statisticians

Police Behavior during Traffic and Street Stops, 2011

HIGHLIGHTS

 Relatively more black drivers (13%) than white (10%) and 

Hispanic (10%) drivers were pulled over in a traffic stop 

during their most recent contact with police. There were 

no statistical differences in the race or Hispanic origin of 

persons involved in street stops.

 Persons involved in street stops were less likely (71%) than 

drivers in traffic stops (88%) to believe that the police 

behaved properly.

 Of those involved in traffic and street stops, a smaller 

percentage of blacks than whites believed the police 

behaved properly during the stop. 

 Drivers pulled over by an officer of the same race or 

ethnicity were more likely (83%) than drivers pulled over 

by an officer of a different race or ethnicity (74%) to believe 

that the reason for the traffic stop was legitimate.

 White drivers were both ticketed and searched at lower 

rates than black and Hispanic drivers.

 Across race and Hispanic origin, persons who were searched 

during traffic stops were less likely than persons who were 

not searched to believe the police behaved properly during 

the stop. 

 About 1% of drivers pulled over in traffic stops had physical 

force used against them by police. Of these drivers, 55% 

believed the police behaved properly during the stop.

 About 6 in 10 persons age 16 or older involved in street 

stops believed they were stopped for a legitimate reason.

 About 19% of persons involved in street stops were 

searched or frisked by police. The majority of persons who 

were searched or frisked did not believe the police had a 

legitimate reason for the search. 

Revised October 27, 2016
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 2

Figure 1

Perceptions that police behaved properly and respectfully during most recent contact with persons age 16 or older, by type of 

contact, 2011

Note: Based on the most recent contact with police during the past 12 months. Detail may not sum to 100% due to missing data and multiple responses. See appendix 

table 1 for estimates and standard errors.

aIncludes being stopped by police as either a driver or a passenger in a motor vehicle. All other tables focus on the driver of the motor vehicle in a traffic stop. 

bIncludes being stopped by police in a public place, not a moving vehicle.

! Interpret with caution. Estimate based on 10 or fewer sample cases or the coefficient of variation is greater than 50%.

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011. 

Persons age 16 or older

with police contact 

62,936,500

Other 

contact

50.8%

Request for 

assistance

38.5%

Police behaved 

properly and 

respectfully

86.4%

Police were not 

respectful

9.0%

Police did not 

behave properly

9.6%

Police behaved 

properly and 

respectfully

65.9%

Police were not 

respectful

22.9%

Police did not 

behave properly

24.5%

Complaint

 filed

4.4%

Complaint 

filed

2.8% !

No complaint 

filed

95.6%

No complaint 

filed

97.2%

Traffic 

accident

8.8%

Anti-crime 

program

participation

3.5%

Traffic stopa

42.0%

Arrest or other

involuntary 

contact

5.0%

Street stopb

2.3%

Involuntary 

contact

49.2%
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 3

About 71% of persons involved in streets stops 

thought the police behaved properly, compared to 

88% of drivers pulled over in traffic stops

In 2011, less than 1% of the 241.4 million U.S. residents 

age 16 or older were involved in a street stop during their 

most recent contact with police (table 1; appendix table 2). 

A greater percentage of males (1%) than females (less than 

1%) were involved in street stops during 2011. Persons ages 

16 to 24 were more likely than persons age 35 or older to be 

involved in street stops. While no differences were observed 

in the percentage of non-Hispanic white, non-Hispanic 

black, and Hispanic populations age 16 or older involved 

in a street stop, among those who were stopped, a smaller 

percentage of blacks (38%) than Hispanics (63%) or whites 

(78%) felt the police behaved properly during the stop.

Traffic stops were a more common form of police contact 

than street stops in 2011. About 10% of the 212.3 million 

U.S. drivers age 16 or older were stopped while operating a 

motor vehicle during their most recent contact with police.1

As with street stops, a greater percentage of male drivers 

(12%) than female drivers (8%) were pulled over in traffic 

stops. Across age groups, the highest percentage of stopped 

drivers was among drivers ages 18 to 24 (18%). A higher 

percentage of black drivers (13%) than white (10%) and 

Hispanic (10%) drivers age 16 or older were pulled over in a 

traffic stop during their most recent contact with police.

A higher percentage of drivers in traffic stops (88%) than 

persons involved in street stops (71%) believed the police 

behaved properly during the stop. White drivers pulled over 

by police (89%) were more likely than black drivers (83%) to 

think that the police behaved properly, while no difference 

was observed between the percentages of stopped white 

drivers and Hispanic drivers who thought that the police 

behaved properly. There was also no statistical difference in 

the percentages of black and Hispanic stopped drivers who 

believed the police behaved properly.

1The driving population includes persons age 16 or older who reported 

driving a few or more times during the year or who were stopped as the 

driver in a traffic stop during 2011.

Table 1

Involuntary contact with police among persons age 16 or older, by demographic characteristics and type of contact, 2011

Street stopsa Traffic stopsb

Percent of stopped persons Percent of stopped drivers

Demographic characteristics

Percent of 

all persons Total

Police behaved 

properlyd

Percent of 

all driversc Total

Police behaved 

properlyd

Total 0.6% 100% 70.7% 10.2% 100% 88.2%

Sex

Male 0.8% 67.5% 69.8% 11.9% 58.8% 86.9%

Female 0.4 32.5 72.7 8.4 41.2 89.9

Race/Hispanic origin

Whitee 0.6% 65.2% 77.6% 9.8% 69.3% 89.4%

Black/African Americane 0.6 12.4 37.7 ! 12.8 12.6 82.7

Hispanic/Latino 0.7 15.3 62.9 10.4 12.2 86.5

American Indian/Alaska Nativee 0.5 ! 0.4 ! 100 ! 15.0 0.6 74.2

Asian/Native Hawaiian/other Pacific Islandere 0.4 ! 3.6 ! 85.0 ! 9.4 4.0 89.5

Two or more racese 1.8 ! 3.1 ! 76.6 ! 13.4 1.3 94.8

Age

16–17 1.5% 8.5% 67.4% 9.0% 1.8% 92.3%

18–24 1.6 31.7 72.1 17.8 19.5 85.1

25–34 0.9 27.1 64.4 12.7 22.4 88.1

35–44 0.4 10.6 81.6 11.3 19.8 87.9

45–54 0.4 10.9 79.7 9.4 17.9 88.7

55–64 0.2 5.5 62.2 ! 7.1 11.4 89.7

65 or older 0.2 5.7 68.8 ! 4.8 7.2 92.3

Note: See appendix table 2 for estimates of the U.S. population and driving population age 16 or older and appendix table 3 for standard errors. 

! Interpret with caution. Estimate based on 10 or fewer sample cases or the coefficient of variation is greater than 50%.

aIncludes persons stopped by police during the past 12 months for whom the most recent contact involved being stopped by police on the street or in public, 

but not in a moving motor vehicle. 

bIncludes persons stopped by police during the past 12 months for whom the most recent contact was as a driver in a traffic stop. 

cPercents based on the driving population age 16 or older, which includes PPCS respondents who reported driving a few times a year or more or were the driver in a 

traffic stop. 

dDenominator includes approximately 2% of respondents who did not know or did not report whether police behaved properly.

eExcludes persons of Hispanic or Latino origin.

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011. 

Revised October 24, 2016
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 4

Traffic stops

Regardless of the reason for the traffic stop, black (67%)

and Hispanic (74%) drivers were less likely than white 

drivers (84%) to believe the reason for the stop was 

legitimate 

In 2011, a greater percentage of white drivers (84%) than 

Hispanic (74%) or black drivers (67%) who were stopped by 

police believed they were pulled over for a legitimate reason 

(table 2). Across all races and Hispanic origin, drivers 

stopped for speeding were among the most likely to perceive 

that the reason for the traffic stop was legitimate (90% 

of white, 83% of Hispanic, and 73% of black drivers). In 

general, drivers who were pulled over and not given a reason 

for the traffic stop were the least likely to think the traffic 

stop was legitimate. For example, 51% of white drivers who 

were stopped without the police giving a reason believed the 

stop was legitimate, whereas 84% who were given a reason 

believed that the stop was legitimate.

Among other reasons for traffic stops that were associated 

with comparatively lower perceptions that the stop was 

legitimate, less than 70% of white (69%), black (69%), and 

Hispanic (64%) drivers who were pulled over for a stop light 

or stop sign violation believed the police had a legitimate 

reason for stopping them. Less than 70% of black drivers 

stopped due to a vehicle defect (69%), a seatbelt or cell 

phone violation (64%), or an illegal turn or lane change 

violation (65%) thought the police had a legitimate reason 

for stopping them. 

Table 2

Perception that reason for traffic stop was legitimate among drivers age 16 or older, by race or Hispanic origin of driver and 

reason for stop, 2011

Percent of stopped drivers

Reason for traffic stop All Whitea Black/AfricanAmericana Hispanic/Latino Othera,b

Any reasons 100% 100% 100% 100% 100%

Police gave reason for the stop

Speeding 46.5 50.1 37.7 39.2 37.3

Vehicle defect 14.1 12.7 19.0 16.5 14.6

Record check 9.7 9.0 14.0 9.7 9.9

Roadside sobriety check 1.3 1.6 0.4 ! 1.0 ! 1.0 !

Seatbelt or cell phone violation 6.6 6.6 6.5 6.5 7.4

Illegal turn or lane change 7.0 6.6 7.0 7.1 10.8

Stop sign/light violation 6.7 6.1 5.5 9.9 9.4

Other reasonc 5.1 4.7 5.3 6.8 5.2

Police did not give reason for the stop 3.1 2.6 4.7 3.3 4.2 !

Percent reporting reason for stop was legitimated

Reason for traffic stop All Whitea Black/African Americana Hispanic/Latino Othera,b

Any reasons 80.0% 83.6% 67.5% 73.6% 78.4%

Police gave reason for the stop

Speeding 87.1 89.6 72.8 83.1 87.3

Vehicle defect 81.2 86.4 69.0 74.4 79.3

Record check 80.0 80.9 83.0 70.7 81.2

Roadside sobriety check 79.4 86.0 -- ! 56.6 ! 68.1 !

Seatbelt or cell phone violation 79.7 84.0 63.8 77.3 69.0 !

Illegal turn or lane change 73.0 75.4 65.0 72.6 67.1

Stop sign/light violation 68.4 68.8 69.2 63.6 74.6

Other reasonc 59.1 65.2 21.6 ! 61.9 67.8 !

Police did not give reason for the stop 44.6 51.0 36.6 ! 18.3 ! 59.8 !

Note: Based on persons for whom the most recent contact with police was as a driver in a traffic stop. See appendix table 4 for standard errors. 

! Interpret with caution. Estimate based on 10 or fewer cases or the coefficient of variation is greater than 50%.

-- Less than 0.05%.

aExcludes persons of Hispanic or Latino origin.

bIncludes persons identifying as American Indian, Alaska Native, Asian, Native Hawaiian, or other Pacific Islander, and persons of two or more races. 

cDenominator includes approximately 3% of white, 6% of black, 3% of Hispanic, and 4% of other race drivers who did not know or did not report whether the reason for 

the stop was legitimate. 

dIncludes reasons such as reckless driving, littering, failure to yield, following too closely, obstructed license plate, and noise violations.

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011. 
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 5

A greater percentage of drivers pulled over by an officer 

of the same race or ethnicity (83%) than drivers stopped 

by an officer of a different race or ethnicity (74%) 

believed the reason for the traffic stop was legitimate 

About 83% of drivers pulled over by an officer of the same 

race or Hispanic origin thought the reason for the traffic 

stop was legitimate, compared to 74% of drivers pulled over 

by an officer of a different race or Hispanic origin (table 3).

2

However, drivers’ perceptions of traffic stop legitimacy 

varied somewhat by the reason for the stop and whether the 

driver and officer were the same race or Hispanic origin. 

When the reason for the stop was speeding, a vehicle 

defect, a roadside sobriety check, or a seatbelt or cell phone 

violation, drivers pulled over by an officer of a different race 

or ethnicity were less likely than drivers pulled over by an 

officer of the same race or ethnicity to perceive the reason 

for the traffic stop to be legitimate. In comparison, a similar 

percentage of drivers stopped for a record check, an illegal 

turn or lane change, or a stop light or stop sign violation 

perceived the stop to be legitimate, regardless of whether 

the officer was the same race or ethnicity as the driver or a 

different race or ethnicity. Whether the driver and officer 

were intraracial (41%) or interracial (42%), the officer’s 

failure to give a reason for the stop resulted in less than half 

of stopped drivers believing the stop was legitimate.

2Data on officer race or Hispanic origin are based on respondent’s perception. 

Table 3

Perception that reason for traffic stop was legitimate among drivers age 16 or older, by reason for stop and whether driver and 

officer were intra- or interracial, 2011

Intraracial driver and officer Interracial driver and officer

Reason for traffic stop

Total stopped 

drivers 

Reason for stop 

was legitimatea Total stopped drivers

Reason for stop 

was legitimatea

Any reasons 100% 83.3% 100% 74.4%

Police gave reason for the stop

Speeding 51.1 89.4 42.3 83.6

Vehicle defect 13.0 84.4 16.7 74.6

Record check 8.7 79.3 9.6 80.8

Roadside sobriety check 1.4 83.4 0.4 ! 38.5 !

Seatbelt or cell phone violation 6.1 86.2 7.2 70.4

Illegal turn or lane change 6.6 75.2 7.3 67.7

Stop sign/light violation 6.0 70.9 7.5 62.3

Other reasonb 4.6 63.6 5.8 45.6

Police did not give reason for the stop 2.4 46.8 3.1 41.8

Note: Based on persons for whom the most recent contact with police was as a driver in a traffic stop. Information on the race or Hispanic origin of the officer is based on 

respondent’s perception. Excludes drivers who were stopped by two or more officers of different races or Hispanic origin and officers whose race or Hispanic origin were 

unknown to the driver. See appendix table 5 for standard errors. 

aDenominator includes approximately 3% of respondents who did not know or did not report whether the reason for the stop was legitimate.

bIncludes reasons such as reckless driving, littering, failure to yield, following too closely, obstructed license plate, and noise violations.

! Interpret with caution. Estimate based on 10 or fewer sample cases or the coefficient of variation is greater than 50%. 

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011. 
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 6

While the majority of drivers pulled over in a traffic stop 

were stopped by white officers, a larger percentage of black 

drivers (14%) than white (4%) or Hispanic (3%) drivers 

were stopped by black officers (table 4). Similarly, a greater 

percentage of Hispanic drivers was stopped by Hispanic 

officers (17%) than were white (3%) or black (6%) drivers.

A similar percentage of white drivers believed the reason 

for the stop was legitimate, regardless of whether they were 

stopped by white, Hispanic, or black officers. While black 

drivers had similar perceptions of police legitimacy when 

pulled over by white (70%) or black (71%) officers, a lower 

percentage of black drivers stopped by Hispanic officers 

perceived the stop to be legitimate (47%). Among Hispanic 

drivers, no differences were observed in perceptions of traffic 

stop legitimacy, regardless of the race or Hispanic origin of 

the officer. 

Among drivers who thought the reason for the stop 

was not legitimate, 65% believed the police behaved 

properly, compared to 94% among drivers who 

thought the stop was legitimate

When the reason for the traffic stop was not seen as 

legitimate, a smaller percentage of white, black, and Hispanic 

drivers believed the police behaved properly during the stop 

than when the reason for the stop was legitimate. Whether 

the driver and officer were intra- or inter- racial, relatively 

fewer whites, blacks, and Hispanics thought the police 

behaved properly when the reason for the stop was perceived 

to be illegitimate. Regardless of the race or Hispanic of the 

officer, over 90% of white, black, and Hispanic drivers who 

believed the stop was legitimate also thought that the police 

behaved properly. Among white and Hispanic drivers who 

believed the police had no legitimate reason for the stop, 

the percentage who also believed that the police behaved 

properly did not vary, regardless of whether the officer was 

white, black, or Hispanic. Among black drivers who believed 

the officer had no legitimate reason for the traffic stop, a 

higher percentage thought the police behaved properly when 

the officer was black (87%) than when the officer was white 

(58%) or Hispanic (55%).

Table 4

Perception that reason for traffic stop was legitimate among drivers age 16 or older, by race and ethnicity of driver and officer and 

driver’s perception that police behaved properly, 2011

Percent of stopped drivers

Police behaved properlyc

Race and ethnicity of driver and officer

Percent of 

all drivers Totala Reason for stop was legitimateb Reason for stop was legitimate

Reason for stop 

was not legitimate

Total 10.2% 100% 80.0% 93.9% 65.0%

White driverd,e 9.8% 100% 83.6% 93.9% 64.5%

White officerd 7.9 81.0 84.0 93.8 67.2

Black/African American officerd 0.4 4.3 82.3 96.6 60.3

Hispanic/Latino officer 0.3 3.3 76.5 98.0 63.5

Black/African American driverd,e 12.8% 100% 67.5% 94.2% 58.7%

White officerd 8.3 65.3 70.2 93.6 58.3

Black/African American officerd 1.8 13.8 70.7 91.6 87.1

Hispanic/Latino officer 0.7 5.7 46.8 100 55.4 !

Hispanic/Latino drivere 10.4% 100% 73.6% 94.7% 60.1%

White officerd 6.7 64.9 74.3 94.2 64.1

Black/African American officerd 0.3 3.2 74.1 94.2 ! 64.3 !

Hispanic/Latino officer 1.7 16.7 77.4 93.8 54.4 !

Other driverd,e 10.5% 100% 78.4% 91.9% 78.7%

White officerd 7.6 72.3 80.3 93.1 75.0

Black/African American officerd 0.3 ! 3.1 ! 52.7 ! 51.2 ! 79.4 !

Hispanic/Latino officer 0.6 ! 5.8 ! 76.9 ! 100 ! 100 !

Note: Based on persons for whom the most recent contact with police was as a driver in a traffic stop. Information on the race or Hispanic origin of the officer is based on 

driver’s perception. See appendix table 6 for standard errors. 

! Interpret with caution. Estimate based on 10 or fewer sample cases or the coefficient of variation was greater than 50%. 

-- Less than 0.05%.

aPercentages do not sum to 100% due to 11% of white drivers, 15% of black drivers, 15% of Hispanic drivers, and 19% of other race drivers who were stopped by officers 

identified as American Indian, Alaska Native, Asian, Native Hawaiian, other Pacific Islander, or two or more races; groups of officers of different races and Hispanic origin; 

and officers whose race or Hispanic origin was unknown to the driver.

bDenominator includes approximately 3% of respondents who did not know or did not report whether the reason for the stop was legitimate. 

cDenominator includes approximately 1% of drivers who thought the stop was legitimate and 6% of drivers who did not think it was legitimate who did not know or did 

not report whether the police behaved properly. 

dExcludes persons of Hispanic or Latino origin.

eIncludes officers identified as American Indian, Alaska Native, Asian, Native Hawaiian, or other Pacific Islander, and persons of two or more races.

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011. 
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 7

In 2011, there were small racial differences in the 

percentage of drivers who were ticketed

About 5% of the 212.3 million drivers age 16 or older were 

pulled over and ticketed in the most recent contact with 

police (table 5). Another 3% of all drivers were pulled over 

and given a verbal or written warning and 1% were allowed 

to proceed with no enforcement action after being stopped. 

A greater percentage of male drivers (6%) were ticketed 

than female drivers (4%), and a greater percentage of black 

(7%) and Hispanic (6%) drivers were ticketed than white 

drivers (5%). A greater percentage of black drivers (2%) 

were stopped and allowed to proceed with a no enforcement 

action than white (1%) and Hispanic (1%) drivers. A greater 

percentage of drivers ages 18 to 24 (10%) were ticketed than 

drivers in any other age group. 

The majority (93%) of stopped drivers who were issued a 

warning believed that the police behaved properly during 

the stop. Regardless of the demographic characteristics of 

the driver, 87% to 95% of drivers who were issued a warning 

after being stopped believed the police behaved properly. 

Among drivers of all sexes, ages, races and Hispanic origin 

ticketed by police, the percentage who believed the police 

behaved properly ranged from 81% to 90%.

Across most demographic characteristics examined, 

stopped drivers who were allowed to proceed without any 

enforcement action were less likely than drivers who were 

issued a warning to believe the police behaved properly. 

Since previous findings in this report suggest an association 

between perceptions of traffic stop legitimacy and 

perceptions that police behaved properly, this may suggest 

that drivers were less likely to believe the reason for the stop 

was legitimate when no enforcement action occurred as a 

result of the stop.

In 2011, 1% of stopped drivers were arrested during the 

stop. The majority of arrested drivers also received a ticket 

or a warning during the stop. Among stopped drivers who 

were arrested, 76% believed the police behaved properly (not 

shown in table).

Table 5

Enforcement actions taken by police against drivers age 16 or older, by driver’s demographic characteristics and perception 

that police behaved properly, 2011

Ticketed Warned Allowed to proceed with no enforcement action

Percent of stopped drivers Percent of stopped drivers Percent of stopped drivers

Race of driver

Percent of 

all drivers

Ticketed 

drivers

Police behaved 

properlya Percent of all drivers 

Warned 

drivers

Police behaved 

properlya Percent of all drivers

Drivers with 

no enforcement

Police behaved 

properlya

All drivers 5.3% 100% 86.6% 3.4% 100% 93.3% 1.4% 100% 82.5%

Sex

Male 6.2% 58.5% 86.2% 3.9% 57.8% 92.4% 1.7% 61.7% 78.6%

Female 4.4 41.5 87.2 2.9 42.2 94.5 1.1 38.3 88.9

Race/Hispanic origin

Whiteb 4.8% 65.5% 87.5% 3.6% 75.5% 94.2% 1.4% 69.2% 84.5%

Black/African Americanb 7.0 13.2 81.1 3.5 10.5 87.4 2.1 14.7 78.9

Hispanic/Latino 6.2 14.0 86.6 2.8 9.9 91.7 1.3 11.0 74.7

Otherb,c 6.7 7.2 89.1 2.5 4.1 94.6 1.3 5.1 83.9

Age

16–17 3.9% 1.5% 88.2% 4.2% 2.5% 94.5% 0.9% ! 1.3% 100 % !

18–24 9.8 20.5 84.4 5.2 17.1 91.5 2.7 21.2 76.9

25–34 7.2 24.1 85.4 4.1 21.6 95.0 1.4 17.5 81.5

35–44 6.1 20.3 86.6 3.9 20.2 92.7 1.3 16.9 79.8

45–54 4.7 17.2 88.3 3.1 17.9 91.8 1.5 20.9 83.5

55–64 3.4 10.6 89.1 2.4 11.7 94.2 1.2 13.4 87.6

65 or older 2.0 5.7 89.9 2.0 9.0 95.4 0.8 8.8 90.8

Note: Based on persons for whom the most recent contact with police was as a driver in a traffic stop. Excludes a small percentage of drivers who were arrested without 

any other enforcement action (0.4%). See appendix table 7 for standard errors. 

! Interpret with caution. Estimate based on 10 or fewer sample cases or the coefficient of variation is greater than 50%. 

aDenominator includes approximately 3% of respondents who did not know or did not report whether police behaved properly.

bExcludes persons of Hispanic or Latino origin.

cIncludes persons identifying as American Indian, Alaska Native, Asian, Native Hawaiian, or other Pacific Islander, and persons of two or more races. 

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011.
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 8

Among black and Hispanic stopped drivers, a similar 

percentage of ticketed and not ticketed drivers 

believed the police behaved properly during the 

traffic stop

Among drivers stopped in traffic stops, there was no 

statistical difference in the percentage of white (50%) and 

black (55%) stopped drivers were ticketed in 2011. Hispanic 

stopped drivers (60%) were more likely than white stopped 

drivers to receive a ticket. A greater percentage of white 

drivers were ticketed when stopped by black officers (64%) 

than white officers (49%) (table 6). However, for black and 

Hispanic drivers stopped by police, the percentage issued 

a ticket did not vary by the race or Hispanic origin of the 

officer. These differences and similarities in enforcement 

practices by race or Hispanic origin of the driver and 

officer may be related to the reason for the traffic stop 

or other factors and do not necessarily reflect biased or 

unbiased treatment.

Among white, black, and Hispanic drivers who were stopped 

and ticketed, the percentage who believed the police behaved 

properly did not vary regardless of whether the officer was 

white, black, or Hispanic. Overall, for most racial and ethnic 

groups, the majority of stopped drivers believed the police 

behaved properly whether a ticket was issued or not.

Table 6

Stopped drivers age 16 or older who were ticketed, by race of officer and driver and driver’s perception that police behaved 

properly, 2011

Percent of stopped driversa

Race of driver and officer

Percent of all drivers 

issued a ticket Ticketed

Police behaved properly

Ticketed drivers Drivers not ticketedb

White driverc,d 4.8% 49.5% 87.5% 91.2%

White officerc 3.9 49.2 87.5 91.6

Black/African American officerc 0.3 63.6 86.5 96.7

Hispanic/Latino officer 0.2 50.2 88.3 91.5

Black/African American driverc,d 7.0% 55.1% 81.1% 84.6%

White officerc 4.7 56.5 80.5 86.3

Black/African American officerc 1.1 63.2 88.9 92.6

Hispanic/Latino officer 0.4 53.4 74.4 ! 78.4 !

Hispanic/Latino driverd 6.2% 60.2% 86.6% 86.4%

White officerc 3.9 58.7 85.0 88.3

Black/African American officerc 0.2 ! 52.9 ! 91.9 ! 80.4 !

Hispanic/Latino officer 1.0 59.1 88.7 79.4

Other driverc,d 6.7% 64.0% 89.1% 89.3%

White officerc 4.8 63.5 89.5 89.5

Black/African American officerc 0.3 89.1 60.2 ! 100 !

Hispanic/Latino officer 0.6 ! 100 ! 100 ! -- !

Note: Based on persons for whom the most recent contact with police was as a driver in a traffic stop. Information on the race or Hispanic origin of the officer is based 

on driver’s perception. Excludes drivers who were stopped by officers identified as American Indian, Alaska Native, Asian, Native Hawaiian, other Pacific Islander, or two 

or more races; drivers stopped by groups of officers of different races and Hispanic origin; and officers whose race or Hispanic origin was unknown to the driver. See 

appendix table 8 for standard errors. 

-- Less than 0.05%.

! Interpret with caution. Estimate based on 10 or fewer sample cases or the coefficient of variation is greater than 50%. 

aDenominator includes about 2% of respondents who did not know or did not report whether police behaved properly.

bIncludes drivers who were given a verbal or written warning or allowed to proceed without any enforcement action.

cExcludes persons of Hispanic or Latino origin.

dIncludes officers identified as American Indians, Alaska Natives, Asians, Native Hawaiians, or other Pacific Islanders, and persons of two or more races. 

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011. 
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 9

Stopped drivers who were searched were less likely 

than drivers who were not searched to believe that the 

police behaved properly

In 2011, 3% of drivers pulled over by police in a traffic stop 

had their person or vehicle searched (table 7). A greater 

percentage of male drivers (4%) than female drivers (2%) 

were searched during traffic stops. Male drivers accounted 

for 76% of searches conducted among stopped drivers. A 

lower percentage of white drivers stopped by police were 

searched (2%) than black (6%) or Hispanic (7%) drivers. A 

greater percentage of stopped drivers ages 18 to 34 (5%) than 

those age 55 or older (1%) was searched during traffic stops. 

Across all demographic groups examined, a smaller 

percentage of drivers who had their person or vehicle 

searched by police during a traffic stop than drivers who 

were not searched believed the police behaved properly. 

Overall, 61% of searched drivers believed the police behaved 

properly, compared to 89% of drivers who were stopped 

but not searched. The percentage of searched drivers who 

believed the police behaved properly did not vary by sex, 

race or Hispanic origin, or age. 

Table 7

Stopped drivers age 16 or older who were searched by police, by driver’s demographic characteristics and perception that 

police behaved properly, 2011

Percent of stopped driversa

Demographic characteristics

Percent of all stopped 

drivers searched by police Searched

Police behaved properly

Searched drivers Drivers not searched

Total 3.5% 100% 61.3% 89.1%

Sex

Male 4.5% 75.7% 61.0% 88.1%

Female 2.1 24.3 62.2 90.5

Race/Hispanic origin

Whiteb 2.3% 46.6% 62.4% 90.0%

Black/African Americanb 6.3 22.8 61.6 84.1

Hispanic/Latino 6.6 23.1 64.8 88.1

Otherb,c 4.4 ! 7.4 ! 42.5 ! 91.3

Age

16–17 1.4% ! 0.7% ! --% ! 93.5%

18–34 4.8 58.0 58.7 88.1

35–54 3.1 33.8 69.8 88.9

55 or older 1.4 ! 7.5 ! 49.0 ! 91.3

Note: Includes respondents for whom the most recent contact with police was as a driver in a traffic stop. See appendix table 9 for standard errors.

-- Less than 0.05%.

! Interpret with caution. Estimate based on 10 or fewer sample cases or the coefficient of variation is greater than 50%. 

aDenominator includes about 6% of searched drivers and 2% of other stopped drivers who did not know or did not report whether the police behaved properly.

bExcludes persons of Hispanic or Latino origin.

cIncludes persons identifying as Native American, Alaska Native, Asian, Native Hawaiian, or other Pacific Islander, and persons of two or more races. 

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011.
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 10

When the police did not ask permission to conduct a 

search, less than half of searched drivers thought the 

officers behaved properly during the traffic stop

Less than half (46%) of drivers believed the police behaved 

properly when a person or vehicle search was conducted 

without the police first asking permission to conduct the 

search or without the police having a perceived legitimate 

reason to conduct the search (table 8). When the police 

asked permission before conducting a search during a traffic 

stop, a greater percentage of drivers believed the police 

behaved properly (72%). Similarly, a greater percentage 

of drivers thought the police behaved properly when they 

believed the police had a legitimate reason for conducting 

the search (86%) than when the reason for the search was 

not seen as legitimate (46%). About 6% of searched drivers 

reported that the police uncovered illegal items during the 

search (not shown in table).

More than half of drivers who experienced police 

use of physical force or verbal threats thought police 

behaved properly

In 2011, 6% of drivers pulled over in traffic stops experienced 

some type of force used against them, from shouting and 

cursing, to verbal threats of force or other action, to physical 

force, including hitting, handcuffing, and pointing a gun 

(table 9). Of the 1% of stopped drivers who experienced 

physical force during the traffic stop, more than half (55%) 

believed the police behaved properly during the contact. A 

similar percentage of drivers who experienced verbal threats 

of force believed the police behaved properly (56%).

Three in 4 (75%) stopped drivers who experienced any type 

of force believed the police actions were unnecessary. About 

two-thirds (65%) of drivers who experienced police use of 

force did not think the force was excessive. Among stopped 

drivers who experienced any type of verbal or physical 

force, 83% who believed the force used or threatened against 

them was necessary also thought police behaved properly, 

compared to 38% of those who did not believe the use of 

force was necessary.

Table 8

Stopped drivers age 16 or older who had their person 

or vehicle searched by police, by perception that police 

behaved properly, 2011

Percent of stopped drivers

Stop characteristics Total

Police behaved 

properlya

All stops 100% 88.2%

Police searched driver or vehicle

No 96.4% 89.3%

Yes 3.5 61.4

Percent of searched drivers

Police asked permission to searchb

No 40.2% 46.0%

Yes 59.8 71.8

Driver thought search was legitimateb

No 61.4% 46.1%

Yes 38.6 85.8

Note: Based on persons for whom the most recent contact with police was as a 

driver in a traffic stop. See appendix table 10 for standard errors. 

aDenominator includes about 6% of searched and 2% of other stopped drivers not 

searched who did not know or did not report whether the police behaved properly.

bBased on the number of drivers who experienced a personal or vehicular search.

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 

Police-Public Contact Survey, 2011. 

Table 9

Type of force used or threatened by police against stopped 

drivers age 16 or older, by perception that police behaved 

properly, 2011

Percent of stopped drivers

Type of force Total

Police behaved 

properlya

All stops 100% 88.2%

Force used

Shouting or cursingb 1.2% 22.0% !

Verbal threatsc 3.4 56.4

Physical forced 1.5 55.0

Percent of drivers who 

experienced force

Driver thought use of force was necessarye

No 74.7% 38.4%

Yes 19.1 83.3

Driver thought use of force was excessivee

No 64.6% 68.3%

Yes 33.3 12.4 !

Note: Includes persons for whom the most recent contact with police was as a 

driver in a traffic stop. See appendix table 11 for standard errors. 

! Interpret with caution. Estimate based on 10 or fewer sample cases or the 

coefficient of variation is greater than 50%. 

aDenominator includes about 3% of respondents who did not know or did not 

report whether the police behaved properly.

bExcludes stopped drivers who experienced verbal threats or physical force.

cIncludes threats of arrest, ticketing, or use of force. Excludes stopped drivers 

who experienced physical force used against them.

dIncludes pushing, grabbing, hitting, kicking, handcuffing, using chemical or 

pepper spray, using an electroshock weapon, or pointing a gun. 

eBased on stopped drivers who had force (shouting or cursing, verbal threats, 

or physcial force) used against them by police. Percent of stopped drivers does 

not sum to 100% due to persons who did not know whether the use of force was 

necessary or excessive. 

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 

Police-Public Contact Survey, 2011.
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 11

Street stops

About 6 in 10 persons involved in street stops believed 

they were stopped for a legitimate reason

In 2011, less than 1% of persons age 16 or older were stopped 

by the police while in a public place (table 10). Among persons 

stopped by the police in a street stop during their most recent 

police contact, at least 41% were stopped because the police 

suspected them of something or they matched the description 

of someone for whom the police were looking. At least 

16% of persons involved in street stops said the police did 

not provide a reason for the stop or the police were seeking 

information about another person or investigating a crime, 

and at least 7% were stopped because the police were 

providing a service. About 20% of persons involved in street 

stops did not report a reason for the stop.

Overall, 64% of persons involved in street stops believed the 

police stopped them for a legitimate reason. Among persons 

who were stopped because the police suspected them of 

something, 61% thought the reason for the stop was legitimate. 

The percentage of persons who thought the reason for the stop 

was legitimate was higher among those who were stopped 

because the police were providing a service (91%) or seeking 

information or investigating a crime (92%). Similarly, compared 

to those who were stopped because the police were investigating 

a crime (90%) or were providing assistance (96%), a lower 

percentage of persons stopped because they were suspected 

of something believed the police behaved properly (68%).

Table 10

Reason for street stops involving persons age 16 or older, by perceptions that stop was legitimate and police behaved 

properly, 2011

Percent of stopped persons

Reason for street stop

Percent of 

all persons Total

Reason for stop 

was legitimatea Police behaved properlyb

Any reasons 0.6% 100% 64.1% 70.7%

Suspected of something or matched description of someone police were looking forc 0.2 40.7 60.8 68.5

Police were seeking information about another person or investigating a crime 0.1 15.5 92.1 89.8

Police were providing a service -- 6.9 90.8 95.9

No reason given by police 0.1 16.5 29.7 49.0

Unknownd 0.1 20.4 68.1 69.8

Note: Based on persons for whom the most recent contact with police involved being stopped by police in public or on the street, not in a moving vehicle. See appendix 

table 12 for standard errors.

-- Less than 0.05%.

aDenominator includes less than 1% of respondents who did know or did not report whether police had a legitimate reason for the stop. 

bDenominator includes about 3% of respondents who did know or did not report whether police behaved properly.

cIncludes street stops in which the respondent was with someone who the police suspected of something or who matched the description of someone for whom they 

were looking. 

dNo reason reported. 

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011. 
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 12

Regardless of the reason for the stop, a slightly higher 

percentage of persons involved in a street stop with an 

officer of the same race or ethnicity believed that the police 

behaved properly (79%) than persons stopped by an officer 

of a different race or ethnicity (62%) (table 11). Persons least 

likely to believe the police behaved properly during street 

stops were those stopped for reasons they did not believe 

were legitimate (38%), persons who were searched without 

a perceived legitimate reason (29%), and persons who had 

force used against them (30%).3

Table 11

Characteristics of persons age 16 or older involved in street 

stops and outcomes of the stop, by perceptions that police 

behaved properly, 2011

Percent of stopped persons

Stop characteristics Total

Police behaved 

properlya

All stops 100% 70.7%

Officer and respondent were the same 

 race or Hispanic originb

No 22.4% 62.3%

Yes 54.5 78.8

Unknownc 23.1 59.8

Reason for stop was legitimate

No 35.6% 37.5%

Yes 64.1 89.5

Searched or frisked

No 78.9% 76.6%

Yes 19.1 53.8

Person thought search was legitimate

No 11.1% 29.5%

Yes 8.0 87.9

Force used

No 74.6% 84.5%

Yes 25.4 30.3

Person thought force was excessive

No 17.3% 44.5%

Yes 7.0 -- !

Note: Based on persons for whom the most recent contact with police involved 

being stopped by police in public or on the street, not in a moving vehicle. See 

appendix table 13 for standard errors. 

 -- Less than 0.05%.

! Interpret with caution. Estimate based on 10 or fewer sample cases or the 

coefficient of variation is greater than 50%. 

aDenominator includes about 4% of respondents who did know or did not 

report whether police behaved properly.

bInformation on the race or Hispanic origin of the officer is based on the 

person’s perception.

cIncludes person who were stopped by two or more officers of different races or 

Hispanic origin and officers whose race or Hispanic origin was unknown to the 

person.

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 

Police-Public Contact Survey, 2011

3Due to small sample sizes, the percentage of persons who had illegal items 

uncovered in the search could not be calculated. 

Police–Public Contact Survey questions pertaining 

to perceptions of police behavior and legitimacy of 

police actions

Perceptions of police behavior

Q. Looking back in this contact, do you feel the police 

behaved properly?

Perceptions of legitimacy of stop

Q. Would you say that the police officer(s) had a legitimate 

reason for stopping you?

Perceptions of legitimacy of search

Q. Do you think the police officers had a legitimate reason to 

search the vehicle (asked of drivers in traffic stops only)?

Q. Do you think that police officers had a legitimate reason 

to search you, frisk you, or pat you down?

Perceptions of police use of force

Q. Did you feel that this/these action(s) [used by police 

against you] was/were necessary?

Q. Did you feel any of the force used or force threatened 

against you was excessive?
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 13

Methodology

Data collection

The Police-Public Contact Survey (PPCS) is a supplement 

to the National Crime Victimization Survey (NCVS). The 

NCVS annually collects data on crime reported and not 

reported to the police against persons age 12 or older from 

a nationally representative sample of U.S. households. The 

sample includes persons living in group quarters (such 

as dormitories, rooming houses, and religious group 

dwellings) and excludes persons living in military barracks 

and institutional settings (such as correctional or hospital 

facilities) and the homeless. (For more information, see the 

Survey Methodology in Criminal Victimization in the United 

States, 2008, NCJ 231173, BJS website, May 2011.)

Since 1999, the PPCS has been administered every 3 years 

at the end of the NCVS interview to persons age 16 or older 

within households sampled for the NCVS. Proxy responders 

and those who complete the NCVS interview in a language 

other than English were not eligible to receive the PPCS. 

The U.S. Census Bureau administered the 2011 PPCS 

questionnaire between July 1, 2011, and December 31, 2011, 

and processed the survey data. Respondents were provided a 

list of specific reasons for having contact with police and were 

asked if they had experienced any of those types of contacts 

during the prior 12 months. For example, persons interviewed 

in July 2011 were asked about contacts that occurred between 

August 2010 and July 2011. Persons who said they had a 

contact during 2011 were asked to describe the nature of the 

contact, and those who had more than one contact were asked 

about only their most recent contact during the period. To 

simplify the discussion of the findings, this report describes 

all contacts reported during the 12 months prior to the 

interviews as 2011 contacts.

PPCS nonrespondents consisted of persons whose 

household did not respond to the NCVS (NCVS household 

nonresponse), persons within an interviewed NCVS 

household who did not respond to the NCVS (NCVS person 

nonresponse), and persons who responded to the NCVS but 

did not complete the PPCS (PPCS person nonresponse). 

The NCVS household response rate was 89% and the 

person response rate was 88%. In 2011, PPCS interviews 

were obtained from 49,246 of the 62,280 individuals age 

16 or older in the NCVS sample (79%). A total of 13,034 

nonrespondents were excluded from the 2011 PPCS as 

noninterviews or as proxy interviews. Noninterviews 

(10,907) included respondents who were not available for 

the interview, those who refused to participate, and nonEnglish-speaking respondents. (Unlike the NCVS interviews, 

PPCS interviews were conducted only in English.) The 

remaining 2,127 were proxy interviews representing 

household members who were unable to participate for 

physical, mental, or other reasons.

To produce national estimates on police-public contacts, 

sample weights were applied to the survey data so that the 

respondents represented the entire population, including 

the nonrespondents. After adjustment for nonresponse, the 

sample cases in 2011 were weighted to produce a national 

population estimate of 241,404,142 persons age 16 or older.

Despite the nonresponse adjustments, low overall response 

rates and response rates to particular survey items can still 

increase variance in these estimates and produce bias when 

the nonrespondents have characteristics that differ from 

the respondents. The Office of Management and Budget 

guidelines require a nonresponse bias study when the overall 

response rate is below 80%. The Bureau of Justice Statistics 

(BJS) and the Census Bureau compared the distributions 

of respondents as well as nonrespondents and nonresponse 

estimates for various household and demographic 

characteristics, and examined their impact on the national 

estimates produced for the 2011 PPCS. The study looked at 

household-level and person-level response rates and found 

some evidence of bias in the rates among blacks and persons 

of Hispanic origin. Blacks accounted for 12% of the U.S. 

population in 2011 but about 11% of PPCS respondents after 

weighting adjustments. Hispanics accounted for 14% of the 

U.S. population but about 12% of the PPCS respondents 

after weighting adjustments. Because the largest bias in 

person nonresponse was observed in the Hispanic origin 

characteristics, future iterations of the PPCS will address 

this issue by administering the survey in languages other 

than English and including Hispanic origin as a factor in the 

noninterview adjustment. Item nonresponse statistics were 

also computed for key survey questions from the PPCS, and 

no evidence of bias was found during the analysis.

Changes to the 2011 PPCS

Since its inception in 1996, the PPCS has captured 

information about in-person (i.e., face-to-face) contacts 

between police and the public. Telephone contacts were 

previously not included. The survey also excluded face-toface interactions in which persons approached an officer or 

an officer initiated contact with them in a social setting or 

because their work brought them into regular contact. In 

March 2010, BJS hosted a series of meetings with subjectmatter experts in the area of policing and police legitimacy 

to initiate discussion and work on substantive changes to 

the PPCS questionnaire. In 2011, based in part on these 

meetings, the PPCS was revised to expand the scope of the 

survey and to better capture contacts with police.

First, to determine if contact occurred and to enhance 

individuals’ recollections about their interactions with 

police over a 12-month period, BJS implemented new 

screening procedures in the 2011 PPCS that describe a 

broad range of situations known to bring people in contact 

with police. Second, the scope of the PPCS was expanded 

to collect information about interactions that people had 

with the police that did not result in a face-to-face contact 
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 14

(e.g., reporting a crime to the police by phone or email). 

Additionally, a new set of questions was added to the 

instrument to collect detailed information about requests 

for police assistance (e.g., reporting a crime or noncrime 

emergency) and contacts in which the police stopped 

someone in a public place or on the street but not in a motor 

vehicle (known as street stops).

These revisions, which included adding new questions 

and reordering existing questions, were significant when 

compared to the 2008 version of the questionnaire. To assess 

the impact of the survey redesign on trends in rates and 

types of contact, BJS administered a split-sample design in 

which a subset of the sample was interviewed using the 2008 

version of the questionnaire, and the remaining sample was 

interviewed using the 2011 version. Based on the evaluation, 

it was determined that a 15/85 split would provide sufficient 

power to measure a 15% change in contact rate. In other 

words, about 85% of the 2011 sample was randomly assigned 

the revised questionnaire and the other 15% received the 

questionnaire designed for the 2008 survey. The Census 

Bureau completed interviews for 41,408 (79%) of the 52,529 

residents who received the revised questionnaire.

The findings in this report are based on data collected from 

the revised questionnaire. An evaluation of the impact of the 

changes to the 2011 PPCS instrument on trends in contacts 

between the police and the public is underway, and the 

results of that assessment will be made available through the 

BJS website.

Standard error computations 

When national estimates are derived from a sample, as is the 

case with the PPCS, caution must be taken when comparing 

one estimate to another estimate. Although one estimate 

may be larger than another, estimates based on a sample 

have some degree of sampling error. The sampling error 

of an estimate depends on several factors, including the 

amount of variation in the responses, the size of the sample, 

and the size of the subgroup for which the estimate is 

computed. When the sampling error around the estimates is 

taken into consideration, the estimates that appear different 

may, in fact, not be statistically different.

One measure of the sampling error associated with an 

estimate is the standard error. The standard error can vary 

from one estimate to the next. In general, for a given metric, 

an estimate with a smaller standard error provides a more 

reliable approximation of the true value than an estimate 

with a larger standard error. Estimates with relatively large 

standard errors are associated with less precision and 

reliability and should be interpreted with caution.

In order to generate standard errors around estimates 

from the PPCS, the Census Bureau produces generalized 

variance function (GVF) parameters for BJS. The GVFs take 

into account aspects of the NCVS complex sample design 

and represent the curve fitted to a selection of individual 

standard errors based on the Jackknife Repeated Replication 

technique. The GVF parameters were used to generate 

standard errors for each point estimate (i.e., numbers or 

percentages) in the report.

In this report, BJS conducted tests to determine whether 

differences in estimated numbers and percentages were 

statistically significant once sampling error was taken into 

account. Using statistical programs developed specifically 

for the NCVS, all comparisons in the text were tested for 

significance. The primary test procedure used was Student’s 

t-statistic, which tests the difference between two sample 

estimates. To ensure that the observed differences between 

estimates were larger than might be expected due to 

sampling variation, the significance level was set at the 95% 

confidence level.

Data users can use the estimates and the standard errors 

of the estimates provided in this report to generate a 

confidence interval around the estimate as a measure of 

the margin of error. The following example illustrates how 

standard errors can be used to generate confidence intervals:

According to the NCVS, in 2011, an estimated 88.2% 

of drivers stopped by police in traffic stops believed 

that the police behaved properly during the contact 

(see table 1). Using the GVFs, BJS determined that the 

estimate has a standard error of 1.13 (see appendix 

table 3). A confidence interval around the estimate was 

generated by multiplying the standard errors by ±1.96 

(the t-score of a normal, two-tailed distribution that 

excludes 2.5% at either end of the distribution). Thus, 

the confidence interval around the estimate is 88.2 ± 

(1.13 X 1.96) or 86.1 to 90.4. In other words, if different 

samples using the same procedures were taken from the 

U.S. population in 2011, 95% of the time the percentage 

of stopped drivers who believed the police behaved 

properly would be between 86% and 90%.

In this report, BJS also calculated a coefficient of variation 

(CV) for all estimates, representing the ratio of the standard 

error to the estimate. CVs provide a measure of reliability 

and a means to compare the precision of estimates across 

measures with differing levels or metrics. In cases where the 

CV was greater than 50%, or the unweighted sample had 

10 or fewer cases, the estimate was noted with a “!” symbol 

(interpret data with caution; estimate is based on 10 or fewer 

sample cases, or the coefficient of variation exceeds 50%).

Many of the variables examined in this report may be related 

to one another and to other variables not included in the 

analyses. Complex relationships among variables were not 

fully explored in this report and warrant more extensive 

analysis. Readers are cautioned not to draw causal inferences 

based on the results presented.
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 15

Appendix table 1

Standard errors and estimates for figure 1: Perceptions that 

police behaved properly and respectfully during most recent 

contact with persons age 16 or older, by type of contact, 

2011

Stop characteristic

Number of 

persons 

16 or older

Standard error

Number Percent

Any contact 62,936,500 1,581,523 ~%

Involuntary contact 30,954,800 1,079,805 1.2%

Traffic stop 26,404,200 982,622 1.1

Driver thought police 

 did not behave properly 2,547,600 218,913 0.7

Compliant filed

Yes 110,900 31,184 1.2

No 2,436,700 212,649 1.5

Driver thought police 

 were not respectful 2,371,700 208,937 0.7

Driver thought police were 

 proper and respectful 22,808,700 899,273 1.1

Street stop 1,433,300 150,720 0.5

Person thought police 

 did not behave properly 351,800 62,186 3.5

Compliant filed

Yes 10,000 8,183 2.3

No 341,800 61,097 2.6

Person thought police 

 were not respectful 327,700 59,542 3.4

Person thought police were 

 proper and respectful 944,600 115,368 4.1

Arrest or other involuntary contact 3,117,300 249,752 0.7

Other contact 31,981,800 1,100,593 1.2%

Voluntary 24,227,400 932,916 1.3

Traffic accident 5,533,100 363,573 1.0

Anti-crime program participation 2,221,300 200,205 0.6

Note: Detail based on the most recent contact during the past 12 months. Detail 

may not sum to total due to missing data or categories that are not mutually 

exclusive. Estimates rounded to the nearest hundred. 

~ Not applicable.

! Interpret with caution. Estimate based on 10 or fewer sample cases or the 

coefficient of variation is greater than 50%.

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 

Police-Public Contact Survey, 2011. 

Appendix table 2

Population of persons age 16 or older and driving 

population age 16 or older, by demographic 

characteristics, 2011

Demographic characteristics

Population age 

16 or older

Driving population 

age 16 or older

Total 241,404,142 212,298,850

Sex

Male 118,267,679 106,632,822

Female 123,136,463 105,666,027

Race/Hispanic origin

White* 167,364,010 153,358,921

Black/African American* 27,763,474 21,322,976

Hispanic/Latino 31,240,097 25,495,436

American Indian/Alaska Native* 1,058,592 845,043

Asian/Native Hawaiian/

 other Pacific Islander* 11,447,990 9,168,427

Two or more races* 2,529,979 2,108,046

Age

16–17 8,060,403 4,323,648

18–24 28,743,383 23,714,718

25–34 41,829,412 38,016,545

35–44 40,680,390 37,756,084

45–54 44,353,446 41,172,146

55–64 37,837,219 34,884,444

65 or older 39,899,889 32,431,265

Note: See appendix table 3 for standard errors.

*Excludes persons of Hispanic or Latino origin.

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 

Police-Public Contact Survey, 2011. 
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 16

Appendix table 3

Standard errors for table 1: Involuntary contact with police among persons age 16 or older, by demographic characteristics 

and type of contact, 2011

Street stops Traffic stops

Population 

age 16 or older

Percent of 

all persons

Percent of stopped persons Driving 

population 

age 16 or older

Percent of 

all drivers

Percent of stopped drivers

Demographic characteristics Total

Police behaved 

properly Total

Police behaved 

properly

Total 22,320 0.1% ~% 3.9% 1,380,721 0.4% ~% 1.1%

Sex

Male 1,968,304 0.1% 4.1% 4.6% 1,928,128 0.5% 1.6% 1.4%

Female 1,978,921 0.1 3.9 6.1 1,923,848 0.4 1.6 1.4

Race/Hispanic origin

White 1,899,202 0.1% 4.1% 4.3% 1,960,731 0.4% 1.6% 1.2%

Black/African American 1,012,560 0.1 2.6 9.8 ! 862,900 0.9 0.9 2.6

Hispanic/Latino 1,085,620 0.1 2.8 9.0 962,142 0.8 0.9 2.4

American Indian/Alaska Native 124,069 0.6 ! 0.4 ! ~ ! 107,481 3.5 0.2 10.5

Asian/Native Hawaiian/other 

 Pacific Islander 582,997 0.2 ! 1.3 ! 13.0 ! 505,194 1.1 0.5 3.3

Two or more races 217,923 0.7 ! 1.3 ! 16.4 ! 193,506 2.3 0.2 3.8

Age

16–17 464,692 0.4% 2.1% 11.4% 309,377 1.4% 0.3% 4.0%

18–24 1,033,650 0.2 3.8 6.2 920,877 1.1 1.2 2.1

25–34 1,281,640 0.2 3.6 7.0 1,215,222 0.8 1.2 1.8

35–44 1,262,079 0.1 2.4 8.6 1,210,524 0.7 1.2 1.9

45–54 1,323,296 0.1 2.4 8.8 1,270,498 0.6 1.1 1.9

55–64 1,211,990 0.1 1.7 14.4 ! 1,157,274 0.6 0.9 2.2

65 or older 1,248,572 0.1 1.7 13.6 ! 1,109,568 0.5 0.7 2.3

~ Not applicable.

! Interpret with caution. Estimate based on 10 or fewer sample cases or the coefficient of variation is greater than 50%.

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011. 

Revised October 24, 2016
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 17

Appendix table 4

Standard errors for table 2: Perception that reason for traffic stop was legitimate among drivers age 16 or older, by race or 

Hispanic origin of driver and reason for stop, 2011

Percent of stopped drivers

Reason for traffic stop All White Black/AfricanAmerican Hispanic/Latino Other

Any reasons ~% ~% ~% ~% ~%

Police gave reason for the stop

Speeding 1.6 1.8 3.2 0.5 4.2

Vehicle defect 1.0 1.1 2.4 0.3 2.9

Record check 0.8 0.9 2.1 0.2 2.4

Roadside sobriety check 0.2 0.3 0.3 ! 0.1 ! 0.7 !

Seatbelt or cell phone violation 0.6 0.7 1.4 0.2 2.1

Illegal turn or lane change 0.7 0.7 1.5 0.2 2.5

Stop sign/light violation 0.6 0.7 1.3 0.2 2.3

Other reason 0.6 0.6 1.3 0.2 1.7

Police did not give reason for the stop 0.4 0.4 1.2 0.1 1.6 !

Percent reporting reason for stop was legitimate

Reason for traffic stop All White Black/African American Hispanic/Latino Other

Any reasons 1.4% 1.4% 3.2% 3.1% 3.8%

Police gave reason for the stop

Speeding 1.5 1.5 4.4 3.7 4.5

Vehicle defect 2.6 2.7 6.0 6.1 8.2

Record check 3.0 3.5 5.6 8.0 9.4

Roadside sobriety check 6.8 6.4 ~ ! 24.6 ! 32.5 !

Seatbelt or cell phone violation 3.5 3.7 9.9 8.8 12.7 !

Illegal turn or lane change 3.8 4.3 9.5 9.0 10.8

Stop sign/light violation 4.0 4.8 10.3 8.4 10.7

Other reason 4.7 5.4 9.0 ! 9.9 15.0 !

Police did not give reason for the stop 5.7 7.2 11.3 ! 10.6 ! 17.3 !

! Interpret with caution. Estimate based on 10 or fewer cases or the coefficient of variation is greater than 50%.

~ Not applicable.

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011. 
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 18

Appendix table 5

Standard errors for table 3: Perception that reason for traffic stop was legitimate among drivers age 16 or older, by reason for 

stop and whether driver and officer were intra- or interracial, 2011

Intraracial driver and officer Interracial driver and officer

Reason for traffic stop

Total stopped 

drivers

Reason for stop 

was legitimate

Total stopped 

drivers

Reason for stop 

was legitimate

All reasons ~% 1.5% ~% 2.3%

Police gave reason for the stop

Speeding 1.9 1.6 2.5 2.6

Vehicle defect 1.1 3.0 1.7 4.4

Record check 0.9 3.9 1.3 5.0

Roadside sobriety check 0.3 7.7 0.2 ! 25.8 !

Seatbelt or cell phone violation 0.7 3.8 1.1 6.5

Illegal turn or lane change 0.8 4.6 1.1 6.6

Stop sign/light violation 0.7 5.0 1.1 6.7

Other reason 0.6 5.9 1.0 7.6

Police did not give reason for the stop 0.4 7.9 0.7 9.9

~ Not applicable.

! Interpret with caution. Estimate based on 10 or fewer sample cases or the coefficient of variation is greater than 50%. 

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011. 

Appendix table 6

Standard errors for table 4: Perception that reason for traffic stop was legitimate among drivers age 16 or older, by race and 

ethnicity of driver and officer and driver’s perception that police behaved properly, 2011

Percent of stopped drivers

Police behaved properly

Race and ethnicity of driver and officer

Percent of 

all drivers Total

Reason for stop 

was legitimate

Reason for stop 

was legitimate

Reason for stop 

was not legitimate

Total 0.4% ~% 1.4% 0.9% 2.7%

White driver 0.4% ~% 1.4% 1.0% 3.4%

White officer 0.4 1.5 1.5 1.1 3.6

Black/African American officer 0.1 0.6 4.6 2.4 12.2

Hispanic/Latino officer 0.1 0.5 5.6 2.1 11.9

Black/African American driver 0.9% ~% 3.2% 1.9% 5.1%

White officer 0.7 3.2 3.7 2.3 6.3

Black/African American officer 0.3 2.1 6.8 4.8 8.6

Hispanic/Latino officer 0.2 1.3 10.8 ~ 14.4 !

Hispanic/Latino driver 0.8% ~% 3.0% 1.8% 5.6%

White officer 0.6 3.3 3.6 2.2 6.7

Black/African American officer 0.1 1.0 12.7 7.8 ! 26.0 !

Hispanic/Latino officer 0.3 2.3 5.8 3.8 13.2

Other driver 1.0% ~% 3.8% 2.8% 7.0%

White officer 0.9 4.1 4.1 2.9 8.9 !

Black/African American officer 0.1 ! 1.3 ! 20.3 ! 27.5 ! 23.6 !

Hispanic/Latino officer 0.2 ! 1.8 ! 12.9 ! ~ ! ~ !

~ Not applicable.

! Interpret with caution. Estimate based on 10 or fewer sample cases or the coefficient of variation was greater than 50%.

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011. 
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 19

Appendix table 7

Standard errors for table 5: Enforcement actions taken by police against drivers age 16 or older, by driver’s demographic 

characteristics and perception that police behaved properly, 2011

Ticketed Warned Allowed to proceed with no enforcement action

Percent of stopped drivers Percent of stopped drivers Percent of stopped drivers

Race of driver

Percent of 

all drivers

Ticketed 

drivers

Police behaved 

properly

Percent of 

all drivers

Warned 

drivers

Police behaved 

properly

Percent of 

all drivers

Drivers with no 

enforcement

Police behaved 

properly

All drivers 0.3% ~% 1.5% 0.2% ~% 1.2% 0.1% ~% 2.5%

Sex

Male 0.4% 2.0% 1.8% 0.3% 2.4% 1.6% 0.2% 3.2% 3.2%

Female 0.3 2.0 1.9 0.2 2.3 1.5 0.1 3.1 3.0

Race/Hispanic origin

White 0.3% 2.0% 1.6% 0.2% 2.1% 1.3% 0.1% 3.0% 2.8%

Black/African 

 American 0.7 1.2 3.4 0.4 1.2 3.7 0.3 2.1 5.7

Hispanic/Latino 0.6 1.2 2.9 0.4 1.2 3.2 0.2 1.8 6.8

Other 0.8 0.9 3.4 0.4 0.7 3.7 0.3 1.2 8.2

Age

16–17 0.9% 0.3% 6.8% 0.9% 0.6% 4.7% 0.4% ! 0.6% ~% !

18–24 0.8 1.5 2.7 0.5 1.6 2.6 0.4 2.5 5.1

25–34 0.6 1.6 2.4 0.4 1.8 1.9 0.2 2.2 5.1

35–44 0.5 1.5 2.5 0.4 1.7 2.3 0.2 2.2 5.3

45–54 0.4 1.4 2.5 0.3 1.6 2.5 0.2 2.4 4.5

55–64 0.4 1.1 2.9 0.3 1.3 2.5 0.2 2.0 4.8

65 or older 0.3 0.7 3.6 0.3 1.1 2.5 0.2 1.6 5.1

~ Not applicable. 

! Interpret with caution. Estimate based on 10 or fewer sample cases or the coefficient of variation is greater than 50%. 

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011.

Appendix table 8

Standard errors for table 6: Stopped drivers age 16 or older who were ticketed, by race of officer and driver and driver’s 

perception that police behaved properly, 2011

Percent of stopped drivers

Race of driver and officer Percent of all drivers issued a ticket Ticketed

Police behaved properly

Ticketed drivers Drivers not ticketed

White driver 0.3% 1.8% 1.6% 1.4%

White officer 0.2 2.0 1.7 1.5

Black/African American officer 0.0 5.7 4.9 3.3

Hispanic/Latino officer 0.0 6.5 5.7 5.0

Black/African American driver 0.7% 3.3% 3.4% 3.4%

White officer 0.5 3.9 4.0 3.8

Black/African American officer 0.2 7.1 5.7 6.1

Hispanic/Latino officer 0.1 10.8 12.7 ! 12.7 !

Hispanic/Latino driver 0.6% 3.3% 2.9% 3.4%

White officer 0.4 3.9 3.6 3.7

Black/African American officer 0.1 ! 14.3 ! 10.6 ! 16.3 !

Hispanic/Latino officer 0.2 6.8 5.6 8.3

Other driver 0.8% 4.3% 3.4% 4.3%

White officer 0.7 4.9 3.8 4.8

Black/African American officer 0.1 12.8 21.1 ! ~ !

Hispanic/Latino officer 0.2 ! ~ ! ~ ! ~ !

~ Not applicable.

! Interpret with caution. Estimate based on 10 or fewer sample cases or the coefficient of variation is greater than 50%. 

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011. 
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 20

Appendix table 9

Standard errors for table 7: Stopped drivers who were searched by police, by driver’s demographic characteristics and 

perception that police behaved properly, 2011

Percent of stopped drivers

Demographic characteristics

Percent of all drivers 

searched by police Searched 

Police behaved properly

Searched drivers Drivers not searched

Total 0.4% ~% 5.8% 1.2%

Sex

Male 0.6% 4.8% 6.5% 1.4%

Female 0.5 4.5 10.6 1.4

Race/Hispanic origin

White 0.4% 5.5% 7.9% 1.2%

Black/African American 1.4 4.4 10.9 2.8

Hispanic/Latino 1.4 4.4 10.7 2.5

Other 1.6 2.6 18.4 ! 2.8

Age

16–17 1.5% ! 0.8% ! ~% ! 3.9%

18–34 0.7 5.5 7.3 1.6

35–54 0.6 5.1 8.7 1.6

55 or older 0.5 2.6 18.6 ! 1.8

~ Not applicable.

! Interpret with caution. Estimate based on 10 or fewer sample cases or the coefficient of variation is greater than 50%. 

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011.

Appendix table 10

Standard errors for table 8: Stopped drivers age 16 or older 

who had their person or vehicle searched by police, by 

driver’s perception that police behaved properly, 2011

Percent of stopped drivers

Stop characteristics Total

Police behaved 

properly

All stops ~% 1.1%

Police searched driver or vehicle

No 0.7% 1.1%

Yes 0.4 5.4

Percent of searched drivers

Police asked permission to search

No 5.3% 8.0%

Yes 5.4 6.2

Driver thought search was legitimate

No 5.4% 6.7%

Yes 5.3 5.8

~ Not applicable.

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 

Police-Public Contact Survey, 2011. 

Appendix table 11

Standard errors for table 9: Type of force used or threatened 

by police against stopped drivers, by driver’s perception that 

police behaved properly, 2011

Percent of stopped drivers

Type of force Total

Police behaved 

properly

All stops ~% 1.1%

Force used

Shouting or cursing 0.2% 6.8% !

Verbal threats 0.4 5.6

Physical force 0.3 7.7

Percent of drivers who 

experienced force

Driver thought use of force was necessary

No 3.9% 4.7%

Yes 3.2 6.6

Driver thought use of force was excessive

No 4.2% 4.9%

Yes 4.0 4.2 !

~ Not applicable.

! Interpret with caution. Estimate based on 10 or fewer sample cases or the 

coefficient of variation is greater than 50%. 

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 

Police-Public Contact Survey, 2011.
POLICE BEHAVIOR DURING TRAFFIC AND STREET STOPS, 2011 | SEPTEMBER 2013 21

Appendix table 12

Standard errors for table 10: Reason for street stops involving persons age 16 or older, by perceptions that stop was legitimate 

and police behaved properly, 2011

Percent of stopped persons

Reason for street stop

Percent of all persons 

in a street stop Total

Reason for stop 

was legitimate

Police behaved 

properly

Any reasons 0.1% ~% 4.1% 3.9%

Suspected of something or matched description of someone police were looking for 0.0 4.1 6.0 5.8

Police were seeking information about another person or investigating a crime 0.0 2.8 5.1 5.7

Police were providing a service ~ 1.9 7.8 5.3

No reason given by police 0.0 2.9 8.1 ! 9.0

Unknown 0.0 3.2 7.7 7.6

~ Not applicable.

! Interpret with caution. Estimate based on 10 or fewer sample cases or the coefficient of variation is greater than 50%.

Source: Bureau of Justice Statistics, National Crime Victimization Survey, Police-Public Contact Survey, 2011. 

Appendix table 13

Standard errors for table 11: Characteristics of persons age 

16 or older involved in street stops and outcomes of the stop, 

by perceptions that police behaved properly, 2011

Percent of stopped persons

Stop characteristics Total

Police behaved 

properly

All stops ~% 3.9%

Person thought officer and respondent

 were the same race or Hispanic origin

No 3.4% 7.7%

Yes 4.2 4.5

Unknown 3.4 7.7

Person thought reason 

 for stop was legitimate

No 4.0% 6.2%

Yes 4.1 3.2

Searched or frisked

No 3.6% 4.0%

Yes 3.1 8.4

Person thought search 

 was legitimate

No 5.0% 9.6%

Yes 4.3 8.2

Force used

No 3.8% 3.6%

Yes 3.5 6.7

Person thought force 

 was excessive

No 5.4% 8.7%

Yes 3.5 0.0 !

~ Not applicable. 

! Interpret with caution. Estimate based on 10 or fewer sample cases or the 

coefficient of variation is greater than 50%. 

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 

Police-Public Contact Survey, 2011.
Office of Justice Programs

Innovation • Partnerships • Safer Neighborhoods

www.ojp.usdoj.gov

The Bureau of Justice Statistics, located in the Office of Justice Programs, U.S. 

Department of Justice, collects, analyses, and disseminates statistical information 

on crime, criminal offenders, victims of crime, and the operation of justice systems 

at all levels of government. William J. Sabol is acting director. 

This report was written by Lynn Langton and Matthew Durose. Matthew Durose 

verified the report.

Morgan Young edited the report. Barbara Quinn and Morgan Young produced the 

report.

September 2013, NCJ 242937