Booster Seat Use in 2007



Traffic Safety Facts
Research Note

DOT HS 810 894

January 2008

Booster Seat Use in 2007
Donna Glassbrenner,* Ph.D., and Tony Jianqiang Ye =
Booster seat use among 4- to 7-year-old children stood at 37
percent in 2007, statistically unchanged from the prior year’s
rate of 41 percent. This result is from the National Survey of
the Use of Booster Seats (NSUBS), the only probability-based
nationwide child restraint survey that observes restraint use
and obtains age by interview. The NSUBS is conducted by
the National Center for Statistics and Analysis of the National Highway Traffic Safety Administration.
The appropriate restraint system for children 4 to 7 is either
a front-facing safety seat or a booster seat, depending on the
child’s height and weight. However, the NSUBS found that
in 2007, 37 percent of children in this age group were using
booster seats (whether high-backed or backless), 13 percent

were restrained in child safety seats, 35 percent were in seat
belts, and 15 percent were unrestrained. These results indicate that as many as one half of children 4 to 7 in the United
States were not being properly protected (35% prematurely
in seat belts and 15% unrestrained).
The 2007 NSUBS survey also found the following:
n In 2007, 46 percent of children age 4 and 5 were restrained
in booster seats.
n The booster seat use rate for children age 6 and 7 dropped
from 36 percent in 2006 to 25 percent in 2007. This decrease
is statistically significant.

Percent of Children Using
the Restraint Type

Restraint Use for Children Age 4 to 7
100%

2006 2007

80%
60%

41%

40%

17%

20%

37%

33%

35%

13%

15%

9%

0%

Safety Seat

Booster Seat

Seat Belt

Unrestrained

Source: National Survey of the Use of Booster Seats, NHTSA’s National Center for Statistics and Analysis, 2006, 2007

Restraint Use for Children Age 4 and 5

100%

2006 2007

80%
60%
40%
20%
0%

45% 46%
28%

19% 21%

19%

14%
8%

Safety Seat

Booster Seat

Seatbelt

Unrestrained

Source: National Survey of the Use of Booster Seats, NHTSA’s National Center for
Statistics and Analysis, 2006, 2007

Percent of Children Using
the Restraint Type

Percent of Children Using
the Restraint Type

100%

Restraint Use for Children Age 6 and 7
2006 2007

80%
54% 55%

60%
36%

40%

25%

16%

20%
0%

9%

1% 4%
Safety Seat

Booster Seat

Seatbelt

Unrestrained

Source: National Survey of the Use of Booster Seats, NHTSA’s National Center for
Statistics and Analysis, 2006, 2007

*Mathematical Statistician, Mathematical Analysis Division, National Center for Statistics and Analysis, NHTSA
=Statistician, URC Enterprises Inc.

NHTSA’s National Center for Statistics and Analysis

1200 New Jersey Avenue SE., Washington, DC 20590



The survey found some decrease in restraint use from 2006
to 2007. For instance, the survey found a drop in restraint use
among 4- to 7-year-olds from 91 percent in 2006 to 85 percent in 2007. However, this could be due in part to improved
training (in this second year of the survey) on what constitutes “use” for front-facing seats and booster seats, and
might not reflect an actual decrease in restraint use in this
age group. See the Section “A Change to the 2007 Survey that
Could Impact Results” on page 6 for more information.

Evidence of Premature Graduation
to Booster Seats

In addition to this data, the NSUBS collects a wealth of information including the types of restraints used and a myriad of
demographic information (age, race, ethnicity, gender, and,
for children only, height and weight) for up to nine child and
adult occupants in each participating vehicle. The purpose
of this Research Note is to highlight the survey’s results on
booster seat use (see the tables on the following pages) for all
booster seat use estimates computed from the survey data.
Additional Research Notes that present results from the
NSUBS in other topic areas, such as on the degree to which
children are restrained in restraint types appropriate for their
size (height and weight) and on race/ethnicity breakouts of
restraint use, are available at the Web site http://www-nrd.
nhtsa.dot.gov/CMSWeb/index.aspx.

From the booster seat use estimates presented in the tables
on the following pages, we see some evidence of premature
graduation. For instance, 21 percent of children who weigh
between 20 and 40 pounds were using booster seats. However, most front-facing safety seats allow weights above
40 pounds. Therefore, according to NHTSA recommendations, many (if not most) of these children should have been
in front-facing safety seats (unless they have outgrown the
seat’s height limits). We note however that some booster
seats have weight limits as low as 30 pounds.

Who Should Be in Booster Seats?
NHTSA’s official guidance** on booster seats is: Once children
outgrow their front-facing seats (usually around age 4 and 40
pounds), they should ride in booster seats, in the back seat,
until the vehicle seat belts fit properly. Seat belts fit properly
when the lap belt lays across the upper thighs and the shoulder belt fits across the chest (usually at age 8 or when they
reach 4’9” tall).

A review of child safety seats on the market finds a wide variation in height and weight limits. Many height limits range
between 36 and 54 inches, and many weight limits range
from 40 to 60 pounds. This research note will consider these
various limits in applying the NHTSA recommendation to
assess the survey results.

Likewise, 16 percent of children who were at most 36 inches
tall were using booster seats. However, most front-facing
safety seats allow heights above 36 inches. Therefore, many
(if not most) of these children should have been in front-facing safety seats (unless they have outgrown the seat’s weight
limits).
The NSUBS provides a rich data source for information
on the premature graduation of children from birth to age
12 to restraint types that are inappropriate for their height
or weight. Please see the companion publication “Child
Restraint Use in 2007—Use of Correct Restraint Types” referenced below for detailed discussions on this topic.

Ages Considered in This Publication
Many 4- to 7-year-olds have outgrown their front-facing safety seats, so many entities study booster seat use among this
age group. However, in this Research Note, we present information on all children age 12 and younger, as the NHTSA
recommendation involves more than age alone.

*
*http://www.nthsa.dot.gov

NHTSA’s National Center for Statistics and Analysis

1200 New Jersey Avenue SE., Washington, DC 20590



Booster Seat Use, by Age, Weight, and Height
2006
Booster Seat Type1

Booster Seat (Overall)
High-Backed Booster Seat
Backless Booster Seat
Booster Seat (Overall)
High-Backed Booster Seat
Backless Booster Seat
Booster Seat (Overall)
High-Backed Booster Seat
Backless Booster Seat
Booster Seat (Overall)
High-Backed Booster Seat
Backless Booster Seat
Booster Seat (Overall)
High-Backed Booster Seat
Backless Booster Seat
Booster Seat (Overall)
High-Backed Booster Seat
Backless Booster Seat
Booster Seat (Overall)
High-Backed Booster Seat
Backless Booster Seat
Booster Seat (Overall)
High-Backed Booster Seat
Backless Booster Seat
Booster Seat (Overall)
High-Backed Booster Seat
Backless Booster Seat
Booster Seat (Overall)
High-Backed Booster Seat
Backless Booster Seat
Booster Seat (Overall)
High-Backed Booster Seat
Backless Booster Seat
Booster Seat (Overall)
High-Backed Booster Seat
Backless Booster Seat

Percentage2

of
Children3 Using
the Booster Type

2007
Standard
Error

Percentage2

of
Children3 Using
the Booster Type

2006-2007 Change
Standard
Error

Children From Birth - 12 Months
NA
1%
1%
NA
NA
NA
NA
NA
NA
Children Age 1-3 Years
19%
3%
14%
3%
12%
5%
9%
2%
6%
5%
5%
1%
Children Age 4-7 Years
41%
6%
37%
5%
25%
7%
22%
4%
16%
5%
15%
2%
Children Age 8-12 Years
8%
3%
5%
2%
4%
1%
2%
1%
4%
3%
3%
1%
Children Age 12 and Younger Who Weigh Less than 20 Pounds
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Children Age 12 and Younger Who Weigh Between 20 and 40 Pounds
25%
6%
21%
3%
16%
7%
14%
2%
9%
5%
7%
1%
NA
NA
NA

Children Age 12 and Younger Who Weigh Between 41 and 60 Pounds
39%
5%
33%
5%
23%
6%
17%
3%
16%
5%
15%
3%
Children Age 12 and Younger Who Weigh More than 60 Pounds
8%
2%
5%
2%
4%
1%
2%
1%
4%
2%
3%
1%
Children Age 12 and Younger Who Are At Most 36 Inches Tall
 20%
6%
16%
3%
12%
7%
11%
2%
8%
6%
5%
1%
Children Age 12 and Younger Who Are Between 37 and 53 Inches Tall
34%
4%
29%
4%
20%
4%
17%
3%
13%
3%
12%
2%
Children Age 12 and Younger Who Are Between 54 and 56 Inches Tall
13%
10%
11%
3%
9%
5%
3%
2%
4%
5%
8%
2%
Children Age 12 and Younger Who Are Taller than 56 Inches
1%
1%
4%
2%
1%
1%
1%
1%
NA
NA
3%
2%

Change in
Percentage Points

Confidence in a
Change in
Percentage4

NA
NA
NA

NA
NA
NA

-5
-3
-1

83%
47%
60%

-4
-3
-1

54%
34%
30%

-3
-2
-1

88%
97%
56%

NA
NA
NA

NA
NA
NA

-4
-2
-2

61%
26%
57%

-6
-6
-1

87%
78%
22%

-3
-2
-1

79%
65%
68%

-4
-1
-3

72%
23%
69%

-5
-3
-1

73%
63%
42%

-2
-6
4

25%
91%
63%

3
0
NA

96%
42%
NA

Booster seats are classified into two types: those with seat backs (“high-backed”) and those without (“backless”).
Estimates might not sum to totals due to rounding.
Survey data was obtained on children age 12 and younger in passenger vehicles at a nationwide probability sample of gas stations, day care centers, recreation centers, and
restaurants in five fast-food chains. Restraint use is observed by trained data collectors prior to or just as the vehicle comes to a stop, except in the case of observation at fastfood drive-through lanes, where restraint use is observed prior to the vehicle reaching the drive-through window.
4 The degree of statistical confidence that the 2007 use rate is different from the 2006 rate. Confidence levels that meet or exceed 90% are formatted in boldface type.
Note: Decreases in restraint use from 2006 to 2007 could be due in part to improved training in the 2007 survey. For more information see “A Change to the 2007 Survey That
Could Affect Results” on Page 6.
NA: Data not sufficient to produce a reliable estimate.
Source: The National Survey of the Use of Booster Seats, NHTSA’s National Center for Statistics and Analysis, 2006-2007
1
2
3

NHTSA’s National Center for Statistics and Analysis

1200 New Jersey Avenue SE., Washington, DC 20590



Distribution of Restraint Types Among Children Age 4-7 by Sub-age Groups
2006
Restraint Type1

Percentage of
Children Observed
in the Restraint
Type2

Rear-Facing Child Safety Seat
Front-Facing Child Safety Seat
Booster Seat (Overall)
High-Backed Booster Seat
Backless Booster Seat
Seat Belt
No Restraint Observed

NA
28%
45%
27%
18%
19%
8%

Rear-Facing Child Safety Seat
Front-Facing Child Safety Seat
Booster Seat (Overall)
High-Backed Booster Seat
Backless Booster Seat
Seat Belt
No Restraint Observed

NA
1%
36%
21%
14%
54%
9%

Rear-Facing Child Safety Seat
Front-Facing Child Safety Seat
Booster Seat (Overall)
High-Backed Booster Seat
Backless Booster Seat
Seat Belt
No Restraint Observed

NA
17%
41%
25%
16%
33%
9%

2007
Percentage of
Children Observed
in the Restraint
Type2
Children Age 4-5 Years
NA
NA
6%
19%
7%
46%
10%
27%
7%
18%
5%
21%
3%
14%
Children Age 6-7 Years
NA
NA
1%
4%
9%
25%
8%
14%
4%
11%
9%
55%
2%
16%
Children Age 4-7 Years
NA
NA
4%
13%
6%
37%
7%
22%
5%
15%
6%
35%
2%
15%

Standard
Error

2006-2007 Change
Standard
Error

Change in
Percentage Points

Confidence in a
Change in
Percentage3

NA
5%
5%
4%
2%
6%
4%

NA
-9
1
0
0
2
6

NA
97%
10%
4%
12%
21%
91%

NA
1%
5%
4%
3%
4%
5%

NA
3
-11
-7
-3
1
7

NA
98%
92%
78%
69%
14%
83%

NA
3%
5%
4%
2%
4%
4%

NA
-4
-4
-3
-1
2
6

NA
79%
54%
34%
30%
26%
91%

1 Survey

data was obtained on children age 12 and younger in passenger vehicles at a nationwide probability sample of gas stations, day care centers, recreation centers, and
restaurants in five fast-food chains.
2 Restraint use is observed by trained data collectors prior to or just as the vehicle comes to a stop, except in the case of observation at fast-food drive-through lanes, where
restraint use is observed prior to the vehicle reaching the drive-through window
3 The degree of statistical confidence that the 2007 use rate is different from the 2006 rate. Confidence levels that meet or exceed 90 percent are formatted in boldface type.
Note: Decreases in restraint use from 2006 to 2007 could be due in part to improved training in the 2007 survey. For more information see “A Change to the 2007 Survey That
Could Affect Results” on Page 6.
NA: Data not sufficient to produce a reliable estimate.
Source: The National Survey of the Use of Booster Seats, NHTSA’s National Center for Statistics and Analysis, 2006-2007

NHTSA’s National Center for Statistics and Analysis

1200 New Jersey Avenue SE., Washington, DC 20590



Survey Methodology
The National Survey of the Use of Booster Seats obtains its data
by sending trained data collectors to a probability sample of
gas stations, day care centers, recreation centers, and restaurants in five national fast-food chains across the United States.
The choice of these types of data collection sites stems from
the necessity of observing restraint use from a close range in
a slow-moving or stopped vehicle (as is required in order to
distinguish a seat belt being used in conjunction with a backless booster seat from a seat belt being used alone), combined
with the desire to capture large numbers of children.
Data collectors approach passenger vehicles appearing to
have child occupants under the age of 13, observe the restraint
use of up to nine occupants in the first three rows of seats
and conduct interviews to obtain the race and ethnicity of all
occupants (obtained in compliance with OMB standards for
such data) and the heights, weights, and ages of child occupants appearing to be under age 13. (The approximate ages
of other occupants (expressed as an age range, such as 1624 years), and the genders of all occupants, are subjectively
assessed by the data collectors.)
In order to capture restraint usage before children unfasten
the restraints, restraint use is observed by the data collectors
prior to or just as the vehicle comes to a stop, except in the
case of observation at fast-food drive through lanes, where
restraint use is observed prior to the vehicle reaching the
drive-through window.
In order to reach as wide an audience as possible, the NSUBS
uses some Spanish-speaking data collectors.

The 2007 survey yielded nearly a 50-percent increase in the
number of occupants observed compared to the 2006 survey.
This could be due in part to eliminating certain questions
from the occupant interviews, shortening the interview time
per vehicle from about 5 minutes in 2006 to about 2 minutes in 2007, thus allowing for the collection of data on more
vehicles per site. The increase in observations in 2007 could
also be due to the addition of some sites to the survey and
increased site participation rates.
The NSUBS uses a complex multistage probability sample,
statistical data editing, imputation of unknown values, and
complex estimation and variance estimation procedures.
See the NHTSA Technical Report referenced below for more
information on these procedures, as well as for more information on the survey’s data collection protocols.
The design of the survey, survey preparation activities, data
collection, estimation, and variance estimation for the NSUBS
were conducted by Westat, Inc., under the direction of the
National Center for Statistics and Analysis in NHTSA under
Federal contract number DTNH22-07-D-00057. The OMB
clearance number for the NSUBS is 2127-0644.

What Do the Survey Results Tell Us? Are the
Results Representative?
By design and necessity, the NSUBS survey data is obtained
from a restricted set of site types, namely gas stations, day
care centers, recreation centers, and restaurants in five fastfood chains. However, the survey uses a probability sample
of these site types, and so its results are representative of children who frequent these types of sites.

This (2007) is the second year for the NSUBS survey. The 2007
survey data is based on the observation of 14,000 occupants,
7,500 of whom were under age 13, in 4,800 vehicles at 38 day
care centers, 134 fast-food restaurants, 218 gas stations, and
40 recreation centers nationwide. The survey interviews covered 6,560 children under age 13, including 330 infants under
1 year old, 1,494 children 1 to 3 years old, 2,471 children 4 to 7
years old, and 2,265 children 8 to 12 years old. The data was
collected between July 19 and August 2, 2007, while the 2006
data was collected between July 17 and July 29, 2006.

For example, the survey result of 37-percent booster seat use
among 4- to 7-year-olds means that among children in this
age range who were taken by passenger vehicles to gas stations, day care centers, recreation centers, fast-food restaurants in 2007, 37 percent were in booster seats. Whether or
not the booster seat use rate for 4- to 7-year-olds who do not
frequent these site types is higher or lower than 37 percent is
an open question, and not one that the NSUBS (or any other
available survey) can answer.

Sites, Vehicles, Occupants, and
Children Age 12 and Younger in NSUBS

How Do These Results Compare With NOPUS?

2006

2007

Percentage
Change

390

430

9%

Vehicles Observed

3,500

4,800

38%

Occupants Observed

10,000

14,000

42%

Children Age 12 and Younger
Observed

5,300

7,500

42%

Children Age 12 and Younger
Interviewed*

4,400

6,600

48%

Numbers of
Data Collection Sites

* Data obtained by interview with an adult occupant.

NHTSA’s National Center for Statistics and Analysis

NHTSA conducts another survey, the National Occupant
Protection Use Survey (NOPUS), which has shed light on the
use of one class of booster seats, namely high-backed booster
seats. The NOPUS has estimated high-backed booster seat
use since 2002. (The most recent NOPUS survey result estimated that 3 percent of 4-7 year old children were using
high-backed booster seats in 2006.) However as the NOPUS
survey results are obtained from the observations of data collectors stationed at roadsides, from which one cannot reliably discern backless boosters, NOPUS cannot provide an
estimate of the percent of children using booster seats. For
more information on the NOPUS data, see the publication
1200 New Jersey Avenue SE., Washington, DC 20590



“Child Restraint Use in 2006” available at http://www-nrd.
nhtsa.dot.gov/CMSWeb/ViewCatalogbyCategory.aspx.

Restraint Types and Definition of Use
The NSUBS uses the following definitions of restraint use:
Rear-Facing Child Safety Seat - The child occupant is in a seat
that sits on top of the vehicle seat in such a way that the child
faces the rear of the vehicle, and the harness straps are across
the child’s front. The harness straps might be secured or not.
Front-Facing Child Safety Seat - The child occupant is in a seat
that sits on top of the vehicle seat in such a way that the child
faces the front of the vehicle, and with harness straps that are
across the child’s front.
High-Backed Booster Seat - The child occupant is in a seat with
a seat back that sits on top of the vehicle seat, and has a seat
belt across the front of the child’s body, whether lap or lap/
shoulder. No harness is in use.
Backless Booster Seat - The child occupant is sitting on a platform with no seat back that sits on top of the vehicle seat, and
has a seat belt across the front of the child’s body, whether lap
or lap/shoulder. No harness is in use.
Seat Belt - Child (or adult) is sitting on the vehicle seat and the
seat belt is across the front of the body (includes lap belts).
Unrestrained - All other cases.

Progress in Reducing Child Fatalities
We note that child occupant fatalities have declined in the
past decade, as demonstrated by NHTSA’s Fatality Analysis
Reporting System (FARS). Booster seats, child safety seats,
and seat belts provide key tools to achieve further fatality
reductions.

1000
800

Age <1

600

Age 1-3

400

Age 4-7

200
2006

2005

2004

2003

2002

2001

2000

1999

1998

Age 8-14
1996

0

1997

Number of Fatalites

Occupant Fatalities Among Children Age 14 and Under
by Age Groups, 1996-2006

Source: Fatality Analysis Reporting System (FARS) , NHTSA’s National Center for
Statistics and Analysis, 1996-2006

A Change to the 2007 Survey That Could Affect
Results
The year 2007 constitutes the second year in which the NSUBS
was conducted. In response to requests from data collectors
after the 2006 survey, additional training was conducted
on what constitutes “use” for front-facing seats and booster seats, particularly regarding that the harness or seat belt
must be across the front of the child’s body. This improved
training could have contributed to the decrease in restraint
use among 4- to 7-year-olds in the 2007 survey, compared to
the 2006 survey findings.

For More Information
The NSUBS, although its primary purpose is to estimate
booster seat use among 4- to 7-year-olds, provides a rich data
source for information on the restraint use of children under
age 13 and on race/ethnicity results on restraint use among
all ages. In particular, the NSUBS provides data on the premature graduation of children age 12 and younger to restraint
types that are inappropriate for their height or weight. This
publication is part of a series that presents overall results
from the survey on these topics. Please see companion publications such as “Child Restraint Use in 2007—Demographic
Results” and “Child Restraint Use in 2007—Use of Correct
Restraint Types” for the latest data on these topics. Detailed
information on the NSUBS survey design and analysis procedures are provided in the NHTSA Technical Report “The
2007 National Survey of the Use of Booster Seats— Methodology Report.” These publications will be available at the
Web site http://www-nrd.nhtsa.dot.gov/CMSWeb/index.
aspx in 2007 or 2008.
For more information on the campaign by NHTSA to increase
child restraint use, see www.nhtsa.gov.

References
1. Child Passenger Safety: A Parent’s Primer, NHTSA,
accessible from http://www.nhtsa.dot.gov/portal/nhtsa_static_file_downloader.jsp?file=/staticfiles/DOT/
NHTSA/Traffic Injury Control/Articles/Associated
Files/4StepsFlyer.pdf. Washington, DC: National Highway Traffic Safety Administration.
2. Glassbrenner, D., The 2007 National Survey of the Use of
Booster Seats – Methodology Report, NHTSA, to appear.
Washington, DC: National Highway Traffic Safety Administration.
3. Glassbrenner, D., & Ye, J., Child Restraint Use in 2006
– Overall Results, NHTSA, DOT HS 810 737, February
2007. Washington, DC: National Highway Traffic Safety
Administration.
4. Glassbrenner, D., & Ye, J., Booster Seat Use in 2006, NHTSA,
DOT HS 810 796, August 2007. Washington, DC: National
Highway Traffic Safety Administration.

NHTSA’s National Center for Statistics and Analysis

1200 New Jersey Avenue SE., Washington, DC 20590