This document is available to the public from the National Technical Information Service, Springfield, VA 22161

U.S. Department

of Transportation

National Highway

Traffic Safety

Administration

DOT HS 809 729 May 2004

Technical Report

Safety Belt Use in 2003 –

Demographic Characteristics

National Center for Statistics and Analysis
Technical Report Documentation Page

1. Report No.

DOT HS 809 729 

2. Government Accession No. 3. Recipient's Catalog No.

5. Report Date

May 2004

4. Title and Subtitle

Safety Belt Use in 2003 – Demographic Characteristics

6. Performing Organization Code

NPO-101

7. Author(s)

Glassbrenner, Donna, Ph.D.

8. Performing Organization Report No.

9. Performing Organization Name and Address 10. Work Unit No. (TRAIS)

Mathematical Analysis Division, National Center for Statistics and Analysis

National Highway Traffic Safety Administration

U.S. Department of Transportation

NPO-101, 400 Seventh Street, S.W.

Washington, D.C. 20590

11. Contract or Grant No.

13. Type of Report and Period Covered

NHTSA Technical Report

12. Sponsoring Agency Name and Address

Mathematical Analysis Division, National Center for Statistics and Analysis

National Highway Traffic Safety Administration

U.S. Department of Transportation

NPO-101, 400 Seventh Street, S.W.

Washington, D.C. 20590

14. Sponsoring Agency Code

15. Supplementary Notes

Abstract

This report presents results on the demographics of safety belt use from the 2003 National Occupant Protection Use Survey 

(NOPUS), with particular emphasis on results that evaluate aspects of the 2003 Click It or Ticket campaign to raise safety belt 

use nationwide. NOPUS provides the only probability-based observational results on belt use on the road in the United States, 

and is conducted annually by the National Center for Statistics and Analysis in the National Highway Traffic Safety 

Administration (NHTSA). 

The principal findings of the 2003 survey include that safety belt use increased substantially among those the advertising 

component of the 2003 campaign sought to reach, namely, males ranging between young adults and adults. The 2003 NOPUS 

also found increased use in urban and suburban areas, and among females in the same young-adult-to-adult age range. The 

latter may be because females were similarly affected by the advertising, or because they might be substantially influenced by 

the other major component of the 2003 campaign, highly visible enforcement activities conducted by police.

17. Key Words

safety belt use, NOPUS, demographics, Click It or Ticket 

campaign

18. Distribution Statement

Document is available to the public through the National Technical 

Information Service, Springfield, VA 22161

http//:www.ntis.gov

19. Security Classif. (of this report)

Unclassified

20. Security Classif. (of this page)

Unclassified

21. No. of Pages

54

22. Price

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 i

TABLE of CONTENTS

1. Executive Summary .....................................................................................1

2. Background: The 2003 Campaign to Raise Safety Belt Use............................2

3. Highlights of the 2003 Survey.......................................................................3

3.1 Use Increases Among Young Adults and Adults, Both Males and Females.................. 3

3.2 Safety Belt Use Increases in Urban and Suburban Areas............................................... 6

3.2 Safety Belt Use Increases in Urban and Suburban Areas............................................... 7

3.3 Restraint Use Among Children, Ages 0-7 ...................................................................... 9

4. Methodology..............................................................................................10

4.1 Conversion Rates .......................................................................................................... 10

4.2 Survey Design............................................................................................................... 12

4.2.1 The NOPUS Design.............................................................................................. 12

4.2.2 Changes in 2003.................................................................................................... 13

5. Additional Tables.......................................................................................14

6. References .................................................................................................23
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 ii

TABLE of FIGURES

Table 1: Safety Belt Use by Gender and Estimated Age ................................................................ 5

Figure 1: Safety Belt Use Among Ages 8 and Up, By Gender....................................................... 6

Table 2: Safety Belt Use by Urbanization...................................................................................... 7

Figure 2: Safety Belt Use by Urbanization..................................................................................... 7

Table 3: Restraint Use by Front Seat Children, Ages 0-7............................................................... 9

Figure 3: The NOPUS Regions.................................................................................................... 15

Table 4: Sample Sizes................................................................................................................... 15

Table 5: Safety Belt Use by Various Characteristics.................................................................... 16

Table 6: Safety Belt Use by Gender and Vehicle Type ................................................................ 16

Table 7: Safety Belt Use by Urbanization and Vehicle Type ....................................................... 17

Table 8: Safety Belt Use by Gender and Urbanization................................................................. 18

Table 9: Safety Belt Use by Gender and Geographic Region...................................................... 18

Table 10: Safety Belt Use by Gender and Ambient Enforcement Law........................................ 19

Table 11: Safety Belt Use by Age and Urbanization.................................................................... 20

Table 12: Safety Belt Use by Age and Geographic Region.......................................................... 21

Table 13: Safety Belt Use by Age and Ambient Enforcement Law ............................................. 22
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 1

1. Executive Summary

In May of 2003, the National Highway Traffic Safety Administration (NHTSA), in conjunction 

with highway safety offices in nearly every State of the U.S., conducted the largest ever campaign 

to increase safety belt use. Various evaluations of this campaign, which used the messaging theme 

“Click It or Ticket”, found the campaign highly successful. Perhaps most strikingly, use 

nationwide rose an unprecedented four percentage points in a single year, from 75% in 2002 to 

79% in 2003. (Solomon et al., 2003; Glassbrenner, 2003)

In addition to highly visible enforcement activities, a major prong of the effort to raise use was a

$24 million nationwide advertising campaign that focused on the demographic of 18-34 year old 

males. In this report we add to the evaluations of the 2003 campaign by reporting on observed 

usage rates by demographic characteristics, such as age and gender, that particularly address the 

advertising component. These rates were obtained from the National Occupant Protection Use 

Survey (NOPUS), which is conducted annually by the National Center for Statistics and Analysis 

in NHTSA and is the only probability-based survey that observes belt use on the road in the United 

States. 

Our main findings are:

• Safety belt use rose among 16-24 year old males and 25-69 year old males, indicating that 

the 2003 advertising campaign was a success. The campaign, whether through its

advertisement or enforcement components, also appeared to reach females in the same age 

ranges. 

• Despite the success in reaching males, use remains statistically lower among males than 

females. 

• Belt use increased in urban and suburban areas of the country in 2003.

These findings supplement results reported in (Glassbrenner, September 2003), which found

increases in safety belt use in the South, in all vehicle types, in all times of day and week, and in 

States governed by “secondary” belt laws. The results in (Glassbrenner, September 2003) are also 

from the NOPUS survey. 

In this paper, sport utility vehicles may be referred to as SUVs.
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 2

2. Background: The 2003 Campaign to Raise

Safety Belt Use

In May of 2003, NHTSA and highway safety offices in nearly every State conducted the largest 

ever campaign to raise safety belt use in the U.S., called the 2003 Click It or Ticket Campaign. 

The campaign involved two components, the combination of which has been shown effective in 

raising use rates – publicity and highly visible enforcement. Law enforcement officers in 43 

States, the District of Columbia, and Puerto Rico wrote 500,000 tickets for nonuse. NHTSA

purchased $8 million advertising on television and radio, and States purchased an additional $16 

million. (Solomon et al., 2003; Tyson, 2003).

The 2003 campaign was much larger than previous campaigns. The next largest campaign

occurred in the previous year, in which 250,000 tickets were reported to NHTSA and $5 million 

was spent on media. For more information on the 2002 and 2003 campaigns, see (Solomon et al, 

2002; Solomon et al., 2003).

The Click It or Ticket advertising in 2003 was designed to reach 18-34 year old males, a

demographic chosen by NHTSA for various reasons. Safety belt use is lower among males than 

females, and among younger adults than older adults, as NOPUS consistently finds. Also, young 

males generally engage in riskier behaviors (Shinar et al., 2001), and this demographic can be 

effectively reached by advertising during certain types of shows, such as sports and news

programs.

The theme of the advertising campaign was “Click It or Ticket”, conveying the message that it is 

illegal not to use safety belts, law enforcement officers are looking for nonuse, and that you will be 

ticketed for nonuse. Both advertising purchased by NHTSA and the States conveyed this

message. These purchased advertisements, whether on radio, television, or in print, ran for two 

weeks, during the period May 12 – May 26, 2003. Television ads were shown largely during 

sports and news programs, such as NASCAR’s Coca Cola 600, ESPN’s Sportscenter, and during 

the NHL Conference Playoffs, but also during other shows, such as Saturday Night Live, viewed 

by a substantial percentage of 18-34 year old males. For information on the content of the

advertisements, including scripts from television and radio advertisements, and a more extensive 

list of shows during which ads were shown, see (Solomon et al., 2003). 

In addition to advertising purchased by NHTSA and the States, the campaign generated a

substantial amount of “earned media,” that is, articles and stories written in response to the

campaign. For instance, a number of stories on local enforcement activities, such as checkpoints 

at which police would be issuing tickets for safety belt use violations, appeared in local

newspapers, and on local radio and television news programs. The earned media was generally 

about the campaign or particular activities, and so, unlike the purchased media, did not generally 

focus on any particular demographic.
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 3

3. Highlights of the 2003 Survey

This section highlights key findings from the 2003 survey. Additional results may be found in 

Section 5.

3.1 Use Increases Among Young Adults and Adults, Both

Males and Females

Because the advertising branch of the 2003 Click It or Ticket campaign was designed to reach 18-

34 year old males, NHTSA was particularly interested in determining whether safety belt use 

increased in this demographic. Consequently NOPUS, which had generally collected demographic 

data in even-numbered years, was supplemented to collect age and gender data in 2003. Due to 

limited funding, the 2003 NOPUS did not collect other information that it usually collects on its 

demographic survey, such as belt use by race and the use of child restraints.

To be consistent with prior NOPUS surveys, the 2003 survey categorized ages into the same adult 

age groups, namely 16-24, 25-69, and 70+, used in past surveys, rather than redefining the age 

groups to include an 18-34 year old category. Had NOPUS used an 18-34 age group in 2003, it 

would not have been able to see whether use increased in this group. Also since data collectors 

determine the age category into which an observed motorist falls subjectively, as opposed to 

interviewing the motorist, an 18-34 year old category in NOPUS would not have captured the 

campaign’s target demographic precisely anyway. 

The survey indicates that the advertising campaign was a success. Safety belt use rose among 16-

24 year old males from 65% in 2002 to 72% in 2003, and among 25-69 year old males from 73% 

to 78%. Use also rose among males overall, from 72% in 2002 to 77% in 2003. Each of these 

increases is statistically significant with 95% confidence. Of course, we cannot isolate the reason 

for these increases, which may have occurred because of the advertisements, the enforcement 

campaigns, some combination of these, or other factors. 

Interestingly, the survey also found increases in use among females in the same age ranges. Use 

rose among 16-24 year old females from 73% in 2002 to 80% in 2003, and in 25-69 year old 

females from 80% to 85%. Perhaps females in these age ranges decided to buckle more often in 

2003 in response to the Click It or Ticket advertisements, although the advertising was not tailored 

to them specifically. It could also be that females in these age ranges used belts more in 2003 as a 

result of the enforcement campaigns, or for some other reason. 

In fact the rise in use among males and females in general was such that use remains statistically 

higher among females than males, a pattern that NOPUS has seen for years. The male-female gap 

remains at 7 percentage points. That is, in 2003 we have the same pattern of use, with females 

remaining at a statistically higher level than males, but with both genders at higher use levels than 

where they were in 2002. 
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 4

Although both males and females showed the same five percentage point increase in observed use, 

the data are mixed as to which gender made the greater improvement. On the one hand, the fivepoint jump was statistically significant (with 99% confidence) for males, but not significant (only 

58% confidence) for females. That is, based on the five-point jumps we saw from a sample of sites 

in 2002 and 2003, we are 99% confident that safety belt use rose among males, but only 58% 

confident that use rose among females.

The level of confidence reflects the design of the NOPUS sample and the numbers of motorists 

observed, as well as the actual belt use rates in 2002 and 2003. The substantially lower confidence 

in an increase in female use could indicate that males improved their use rates, while females 

might have stayed the same. However note that Table 1 indicates a (statistically insignificant) 

decline in use among 8-15 year old females, and this may have contributed to the lower level of 

female significance. Also the lower female confidence could simply reflect that fewer females 

were observed than males in both survey years. About 19,000 males were observed in 2003 and 

27,000 in 2002, compared to 16,000 females in 2003 and 23,000 in 2002. (The 2003 survey

observed more motorists than the 2002 survey because it collected data during a greater total 

amount of time. See Section 4.2 for more information.)

On the other hand the five-point jump in each gender indicates that females made greater strides 

than males because the females started at a higher use rate in 2002. Nonuse among males 

decreased by 18%, from 29% in 2002 to 23% in 2003, while that for females fell 24%. Although 

the NOPUS use estimates reflect a “snapshot” of use on the roads, and not the percentage of the 

male and female populations that buckle to some specified degree, these reductions in nonuse 

indicate that roughly a quarter of female nonusers in 2002 converted to users in 2003, compared to 

18% for males. (We do not mean to suggest by our choice of words that these “conversions” 

reflect permanent changes in behavior.) We explain this example in greater detail in the section 

“Conversion Rates”.
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 5

Table 1: Safety Belt Use by Gender and Estimated Age

Use in 2003 Use in 2002 2002-2003 Change

Motorist Group

Estimate

1

Standard 

Error

Estimate

1

Standard 

Error

Estimate

2

Standard 

Error

Degree of 

Confidence 

that Use 

Changed

3

Conversion 

Rate

4

Males 77% 2% 72% 1% 5% (S) 2% 99% 18%

ages 8-15 84% 4% 78% 5% 6% 6% 65% 27%

ages 16-24 72% 3% 65% 2% 7% (S) 3% 96% 20%

ages 25-69 78% 2% 73% 1% 5% (S) 2% 99% 19%

ages 70+ 83% 4% 80% 2% 3% 4% 50% 15%

Females 84% 2% 79% 1% 5% 6% 58% 24%

ages 8-15 77% 13% 84% 3% -7% 14% 40% -44%

ages 16-24 80% 3% 73% 2% 7% (S) 4% 95% 26%

ages 25-69 85% 2% 80% 1% 5% (S) 2% 99% 25%

ages 70+ 83% 8% 82% 2% 1% 8% 11% 6%

1

 An "H" or "L" indicates use that is statistically high or low in its category.

2

 An "S" indicates that use is statistically higher in 2003 with 90% confidence.

3

 The degree of statistical confidence in the assertion that use in 2003 was different than use in 2002.

4

 The conversion rate is the percentage reduction in safety belt nonuse.

Source: National Center for Statistics and Analysis, NHTSA, National Occupant Protection Use Survey
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 6

Figure 1: Safety Belt Use Among Ages 8 and Up, By Gender

Source: National Center for Statistics and Analysis, NHTSA, National 

Occupant Protection Use Survey

50%

60%

70%

80%

90%

100%

2002 2003

Belt Use, in Percent

Males, ages 8-15 Males, ages 16-24 Males, ages 25-69

Males, ages 70+ Females, ages 8-15 Females, ages 16-24

Females, ages 25-69 Females, ages 70+
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 7

3.2 Safety Belt Use Increases in Urban and Suburban Areas

Safety belt use in urban areas increased from 72% in 2002 to 79% in 2003, and in suburban areas 

from 76% to 81%. These are statistically significant with 90% confidence. One quarter of 

nonusers in urban areas were converted to users. (See Section 4.1 for an explanation of conversion 

rates.) Use in rural areas remained statistically unchanged at 74% in 2003. 

Table 2: Safety Belt Use by Urbanization

Use in 2003 Use in 2002 2002-2003 Change

Motorist Group

Estimate

1

Standard 

Error

Estimate

1

Standard 

Error

Estimate

2

Standard 

Error

Degree of 

Confidence 

that Use 

Changed

3

Conversion 

Rate

4

Urban motorists 79% 4% 72% 2% 7% (S) 4% 93% 25%

Suburban motorists 81% 2% 76% 1% 5% (S) 2% 96% 21%

Rural motorists 74% 3% 73% 2% 1% 3% 27% 4%

1

 An "H" or "L" indicates use that is statistically high or low in its category.

2

 An "S" indicates that use is statistically higher in 2003 with 90% confidence.

3

 The degree of statistical confidence in the assertion that use in 2003 was different than use in 2002.

4

 The conversion rate is the percentage reduction in safety belt nonuse.

Source: National Center for Statistics and Analysis, NHTSA, National Occupant Protection Use Survey

Figure 2: Safety Belt Use by Urbanization

In NOPUS, data collectors classify sites “Urban”, “Suburban”, or “Rural” subjectively as they visit 

each site. Urbanization is not assessed through independent means, such as by using data on

population density. Consequently, the NOPUS urbanization categories tend to reflect the

characteristics of the immediate area surrounding a site, as opposed to the population density of the 

city or town in which the site is located. For instance a developed downtown area of a sparsely –

50%

60%

70%

80%

90%

100%

2002 2003

Belt Use, in Percent

Urban motorists Suburban motorists Rural motorists

Source: National Center for Statistics and Analysis, NHTSA, National Occupant 

Protection Use Survey
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 8

populated town might well be classified as suburban or rural (although not likely “urban”). An 

advantage of using subjective classification is that it can capture changes in the sites’ character 

quickly, while a disadvantage is inconsistency, since different data collectors may categorize the 

same site differently. 
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 9

3.3 Restraint Use Among Children, Ages 0-7

NOPUS generally collects an extensive set of child restraint data in its demographic survey. 

NOPUS traditionally observes the use of various types of restraints used by children (forwardfacing safety seat, rear-facing safety seat, booster seat, and safety belt) for various age ranges of 

children (e.g. ages 0, 1-3, and 4-7), in both front and rear seats of vehicles. See (Glassbrenner, 

March 2003) for a detailed report on the 2000 and 2002 data. 

However, due to limited funding, the 2003 survey observed only a collapsed age range of children 

(ages 0-7) in the front seat, and only observed whether these children were restrained, without 

noting the type of restraint used. Children were counted as “restrained” if their shoulder belt was 

in use, whether it was used alone or in conjunction with some type of child seat (such as a booster 

seat). Note that not all child safety seats use the vehicle’s shoulder belt. The findings of this 

observation are presented in Table 3.

In order to make comparisons between the 2002 and 2003 data, the 2002 data were recomputed for 

the restricted subpopulation of children observed in 2003. That is, we took the data on front seat 

children in 2002, and collapsed the age ranges to a single 0-7 year old group. Consequently the 

2002 estimated use rate of 83% in Table 3 differs from the use rate of 88% for 0-7 year olds in 

(Glassbrenner, March 2003), which reflects all seating positions.

Table 3: Restraint Use by Front Seat Children, Ages 0-7

NHTSA recommends that all children 12 and under should sit the back seat at all times, especially 

when the vehicle has active front passenger air bag(s). (Hurd, 2002; Hurd, 2004) We do not mean 

to suggest by Table 3 that the front seat is a safe seating position for children in this age range, 

even when they are restrained. 

Use in 2003 Use in 2002 2002-2003 Change

Motorist Group

Estimate

1

Standard 

Error

Estimate

1

Standard 

Error

Estimate

2

Standard 

Error

Degree of 

Confidence 

that Use 

Changed

3

Conversion 

Rate

4

Children Ages 0-7 80% 7% 83% 4% -3% 8% 30% -18%

1

 An "H" or "L" indicates use that is statistically high or low in its category.

2

 An "S" indicates that use is statistically higher in 2003 with 90% confidence.

3

 The degree of statistical confidence in the assertion that use in 2003 was different than use in 2002.

4

 The conversion rate is the percentage reduction in safety belt nonuse.

Source: National Center for Statistics and Analysis, NHTSA, National Occupant Protection Use Survey
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 10

4. Methodology

4.1 Conversion Rates

Surveys that measure the percentage of a population that engages in a particular behavior, such as 

the use of safety belts, frequently evaluate improvement according to percentage point increases in 

the percentages of people who perform the behavior. According to this measure, males and

females would appear to have shown similar improvements in safety belt use in 2002-2003, since 

both increased their use rates by five percentage points. 

However, it was easier for males to increase five percentage points, because they needed to

influence the behavior of a smaller portion of their nonusers to achieve this result. In 2002, 28% of 

males did not use safety belts, compared to 23% in 2003, an 18% reduction. That is, to increase 

their use by five percentage points, males changed the behavior of 18% of their nonusers. The 

corresponding percentage reduction in nonuse for females was 24%, i.e. females changed the 

behavior of nearly a quarter of their nonusers. That is, to increase use by five percentage points, 

males needed to change the behavior of a smaller fraction of their ill-behaving members because 

they started at a higher nonuse rate. (Here we are treating the NOPUS estimates as if they

represented the percentage of males who buckle up to some degree. As explained in the next 

section, this is not true, but it illustrates the point.)

As we see in the previous paragraph, a fairer measure of improvement is the percentage reduction 

in nonuse, because it captures the amount of work that needs to be done to effect the change. We 

call the percentage reduction in nonuse the “conversion rate”. That is, the conversion rate for 

males in the period 2002-2003 is 18%, while that for females in the same period was 24%. Note 

that the conversion rate is negative when use declines. 

As we will see in the next section, the NOPUS estimates do not measure percentages of the 

population that buckled up, but rather a “snapshot” of use on the road. That is, if everyone froze at 

some (daylight) time in 2003, we would estimate that 77% of the male motorists (in a front 

outboard seat of a passenger vehicle) on the road at the time would be buckled up. Consequently, 

the 18% reduction in nonuse really means that there were 18% fewer unbelted males in the 2003 

snapshot than in the 2002 snapshot. Thus thinking of the conversion rate as representing the 

percentage of the (in this case, male) population who were converted to using safety belts is not 

entirely accurate, but this interpretation provides a useful tool for assessing improvements in use 

and for comparing the relative improvements of different subpopulations, such as the

accomplishments of males versus females. 

It is important to keep in mind when considering conversion rates that these do not reflect

permanent changes in behavior. That is, we think of 18% of males as being “converted” to using 

belts, but male belt use may well decline in the future. 

Note also that conversion rates are based on measured increases in use, but we might or might not 

have statistical confidence that use increased at all. Recall from Section 3.1 that although the data 

indicated that both males and females experienced five-point jumps in use, statistically speaking, 
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 11

we are only confident in the assertion that males increased their use, having a relatively small 

degree of confidence (58% confidence) that female use increased. However, the calculation of a 

conversion rate is valid in each case. That is, we would still estimate that 24% of females were 

converted in 2003, even though we are only 58% confident that female use improved at all. 

Although this may seem contradictory, the first assertion represents our best measurement of a 

quantity (the percentage reduction in nonuse), while the second reflects our confidence in an

assertion (the assertion that use increased). In a sense, the data give contrary indications on the 

increase in use among females. 

In summary, the conversion rate reflects the percentage of nonusers whose behavior was modified. 

It is a fairer measure of the improvement in use rates than the percentage point increase in use 

because it reflects the amount of effort needed to achieve that increase.
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 12

4.2 Survey Design

4.2.1 The NOPUS Design

The National Occupant Protection Use Survey is the only probability-based observational survey 

of safety belt use on the nation’s roads. Certain aspects of its design, some arising from practical 

restrictions imposed by its observational nature, are important to understand in order to properly 

interpret the NOPUS estimates. 

In order to observe use as it actually occurs without influencing the results, NOPUS observes 

motorists on the road without stopping vehicles or interviewing motorists. Observations are made 

either from the roadside or from a moving vehicle. Due to practical restrictions on observing in 

these conditions, the survey restricts its belt use observations to observing the shoulder belt use of 

the driver and right front passenger during daylight hours (specifically, 8 AM – 6 PM). The 

substantial number of vehicles with tinted windows in the rear seat makes it challenging to observe 

rear seat use. In addition, it is difficult to observe the rear seat through the windshield, as would 

often be attempted at roadside vantage points, because the front seat often obstructs the view, 

especially in taller vehicles such as SUVs. However, we will investigate this further in the 2004 

NOPUS. Consequently at this time the NOPUS estimates do not reflect lap belts, the rear seats, or 

nighttime use. 

The NOPUS estimator produces “snapshots” of use. For instance, we would estimate that if

everyone froze on the road in 2003 (during daytime), about 77% of males (in the front outboard 

seats) would be belted (with shoulder belts). Consequently, the NOPUS estimates do not

represent the percentages of motorists who buckle up to some specified degree (e.g. at least half 

the time). The latter estimates are more frequently found in telephone surveys of use, such as 

(Block, 2001).

The NOPUS sample design uses a stratified cluster sample described in (Glassbrenner, 2002). 

Demographic data is collected at about 1,200 sites. See the same 2002 report for descriptions of 

variance calculations and for more information on the estimation formula that produces snapshots 

from data collected on vehicles passing a site. 

Demographic data are collected at intersections that are controlled by a stop sign or stoplight, 

where slowed traffic gives data collectors more time to assess characteristics such as age and 

gender. This data is collected in what NOPUS calls its Controlled Intersection Study. There is 

reason to believe that belt use is higher at controlled intersections, since these occur more

frequently in more populated areas, and NOPUS consistently finds higher (although not

statistically higher) use in urban areas. Consequently NOPUS’s demographic estimates are

adjusted using data the survey collects at general intersections, from the NOPUS Moving Traffic 

Study, so as to remove this possible bias.

NOPUS was conducted during a 21-day period, from June 2, 2003 to June 22, 2003. This was 

shortly after the 2003 Click It or Ticket campaign ended. Research indicates that safety belt use 
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 13

rises sharply during and shortly after a campaign, and then drops off slightly, for a net gain in use. 

(Solomon et al., 1999) Consequently, the NOPUS use rates may reflect levels that were

temporarily sustained. However, since the 2002 NOPUS was also conducted shortly after a

campaign, the 2002-2003 changes in NOPUS estimates reflect actual annual changes, and not the 

larger increase one expects to see between just before and just after a campaign.

For additional detail on the NOPUS design, see (Glassbrenner, 2002) and (Glassbrenner,

September 2003). 

4.2.2 Changes in 2003

The demographic estimates were improved in 2003, in that they used independent traffic counts. 

Counts of the vehicles that pass the observation site in some relatively short time period, such as 5 

or 10 minutes, are key elements of the estimation process in producing “snapshots” of use. See 

(Glassbrenner, 2002) for details. Prior to 2003, the NOPUS demographic estimates used traffic 

counts that were collected during a time in which nondemographic data (such as use by vehicle 

type and region of the country) was observed. In 2003, the data collectors conducted separate 

traffic counts when collecting demographic data, and the demographic estimates use these counts, 

which more accurately reflect traffic volume at the time of data collection. 

The duration of the collection of demogr aphic data was shortened in 2003 because of limited 

funding. Previous surveys observed demographic characteristics for 40 minutes per site, while the 

2003 survey collected demographic data for 15-20 minutes. (Two-person teams observed data for 

15 minutes, while single data collectors observed for 20 minutes to give them time to collect more 

data.) In the future, we intend to return to a 40-minute data collection period.

The NOPUS survey is in the process of phasing in additional improvements in data collection 

technology that have not yet affected the collection of demographic data. The NOPUS Moving 

Traffic Study is moving towards a paperless data collection through the use of specially

programmed Personal Data Assistants (PDAs), and towards the collection of interstate data from 

vehicles traveling the interstate. For more information on these data collection methods, see 

(Glassbrenner, September 2003). For practical reasons, the NOPUS Controlled Intersection Study, 

from which the estimates in this report were derived, continue to use for the time being NOPUS’ 

traditional data collection methods (collecting data on paper forms, and observing interstate traffic 

at exit ramps). We continue to investigate expanding these improved data collection methods to 

the greatest extent possible in the NOPUS. 
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 14

5. Additional Tables

With NOPUS observing so many characteristics of motorists (e.g. age, gender, race) and their 

surroundings (e.g. vehicle type, urbanization, and geographic region), many cross tabulations are 

possible. We present below the one-way tables, along with several two-way tables that we find of 

intrinsic interest. 

The tables in this paper contain estimated use rates with their associated standard errors. The 

standard error of an estimate is a measure of the possible error incurred by sampling. One expects 

the actual value being estimated to fall within twice the standard error of the estimated value. For 

instance, we would say with 95% confidence that the actual safety belt use in urban areas is in the 

range 71% - 87%. 

These tables also include some categories for which use was observed in (Glassbrenner, September 

2003), namely the ambient belt law, NOPUS regions, and the time of day and week. Safety belt 

laws are categorized as either “primary", meaning that police may stop and ticket a motorist simply 

for belt nonuse, or “secondary”, meaning that a motorist must be stopped for another infraction, 

such as an expired license tag before being ticketed for nonuse. In 2003, 20 States, the District of 

Columbia, and Puerto Rico had primary laws, while 29 States had secondary laws, and one State 

(New Hampshire) effectively had no safety belt law. (In New Hampshire, it is legal for motorists 

over the age of 18 to be unbelted.) In 2003, two states passed primary laws, namely Illinois and 

Delaware. 

NOPUS divides the country into four regions as follows: 

Northeast: CT, MA, ME, NH, NJ, NY, PA, RI, VT 

Midwest: IA, IL, IN, KS, MI, MN, MO, ND, NE, OH, SD, WI

South: AL, AR, DC, DE, FL, GA, KY, LA, MD, MS, NC, OK, SC, TN, TX, VA, WV

West: AK, AZ, CA, CO, HI, ID, MT, NM, NV, OR, UT, WA, WY
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 15

Figure 3: The NOPUS Regions

Table 4: Sample Sizes

Numbers of 2003 2002

Sites 1,169 1,141

Vehicles 27,069 37,934

Front Seat Occupants 35,161 3,799

Ages 0-7 271 677

Ages 8-15 646 936

Ages 16-24 5,769 6,055

Ages 25-69 25,660 38,176

Ages 70+ 2,815 4,330

Source: National Center for Statistics and Analysis, NHTSA, National Occupant Protection Use Survey

The 2003 NOPUS had fewer observations, because it observed at each site for about half of the 

time. Each site was observed for 40 minutes for the 2002 NOPUS and 15-20 minutes for the 2003 

NOPUS. 

Source: National Center for Statistics and Analysis, NHTSA, National Occupant 

Protection Use Survey
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 16

Table 5: Safety Belt Use by Various Characteristics

Use in 2003 Use in 2002 2002-2003 Change

Motorist Group

Estimate

1

Standard 

Error

Estimate

1

Standard 

Error

Estimate

2

Standard 

Error

Degree of 

Confidence 

that Use 

Changed

3

Conversion 

Rate

4

Urban motorists 79% 4% 72% 2% 7% (S) 4% 93% 25%

Suburban motorists 81% 2% 76% 1% 5% (S) 2% 96% 21%

Rural motorists 74% 3% 73% 2% 1% 3% 27% 4%

Males 77% 2% 72% 1% 5% (S) 2% 99% 18%

Females 84% (H) 2% 79% (H) 1% 5% 6% 58% 24%

Ages 8-15 81% 6% 82% 3% -1% 2% 40% -6%

Ages 16-24 75% 2% 69% 2% 6% (S) 2% 99% 19%

Ages 25-69 80% 2% 76% 1% 4% (S) 2% 95% 17%

Ages 70+ 81% 6% 82% 1% -1% 3% 29% -6%

1

 An "H" or "L" indicates use that is statistically high or low in its category.

2

 An "S" indicates that use is statistically higher in 2003 with 90% confidence.

3

 The degree of statistical confidence in the assertion that use in 2003 was different than use in 2002.

4

 The conversion rate is the percentage reduction in safety belt nonuse.

Source: National Center for Statistics and Analysis, NHTSA, National Occupant Protection Use Survey

Table 6: Safety Belt Use by Gender and Vehicle Type

Use in 2003 Use in 2002 2002-2003 Change

Motorist Group

Estimate

1

Standard 

Error

Estimate

1

Standard 

Error

Estimate

2

Standard 

Error

Degree of 

Confidence 

that Use 

Changed

3

Conversion 

Rate

4

Males 77% 2% 72% 1% 5% (S) 2% 99% 18%

in passenger cars 79% 2% 74% 2% 5% (S) 2% 98% 19%

in vans & SUVs 79% 3% 74% 2% 5% (S) 2% 99% 19%

in pickup trucks66% (L) 3% 65% (L) 2% 1% 2% 33% 3%

Females 84% 2% 79% 1% 5% 6% 58% 24%

in passenger cars 84% 2% 80% 1% 4% 6% 50% 20%

in vans & SUVs 89% 2% 82% 1% 7% 4% 89% 39%

in pickup trucks 74% 6% 71% (L) 4% 3% 12% 19% 10%

1

 An "H" or "L" indicates use that is statistically high or low in its category.

2

 An "S" indicates that use is statistically higher in 2003 with 90% confidence.

3

 The degree of statistical confidence in the assertion that use in 2003 was different than use in 2002.

4

 The conversion rate is the percentage reduction in safety belt nonuse.

Source: National Center for Statistics and Analysis, NHTSA, National Occupant Protection Use Survey
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 17

Table 7: Safety Belt Use by Urbanization and Vehicle Type

Use in 2003 Use in 2002 2002-2003 Change

Motorist Group

Estimate

1

Standard 

Error

Estimate

1

Standard 

Error

Estimate

2

Standard 

Error

Degree of 

Confidence 

that Use 

Changed

3

Conversion 

Rate

4

Urban motorists 79% 4% 72% 2% 7% (S) 4% 93% 25%

in passenger cars 81% 4% 72% 3% 9% (S) 4% 99% 32%

in vans & SUVs 82% 5% 72% 3% 10% (S) 6% 91% 36%

in pickup trucks 60% (L) 7% 69% 3% -9% 7% 79% -29%

Suburban motorists 81% 2% 76% 1% 5% (S) 2% 96% 21%

in passenger cars 83% 2% 78% 2% 5% (S) 2% 96% 23%

in vans & SUVs 85% 3% 79% 1% 6% (S) 3% 98% 29%

in pickup trucks 70% (L) 3% 69% (L) 2% 1% 3% 24% 3%

Rural motorists 74% 3% 73% 2% 1% 3% 27% 4%

in passenger cars 76% 4% 79% 1% -3% 4% 50% -14%

in vans & SUVs 83% 2% 78% 2% 5% (S) 2% 96% 23%

in pickup trucks 62% (L) 4% 54% (L) 5% 8% (S) 5% 92% 17%

1

 An "H" or "L" indicates use that is statistically high or low in its category.

2

 An "S" indicates that use is statistically higher in 2003 with 90% confidence.

3

 The degree of statistical confidence in the assertion that use in 2003 was different than use in 2002.

4

 The conversion rate is the percentage reduction in safety belt nonuse.

Source: National Center for Statistics and Analysis, NHTSA, National Occupant Protection Use Survey
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 18

Table 8: Safety Belt Use by Gender and Urbanization

Use in 2003 Use in 2002 2002-2003 Change

Motorist Group

Estimate

1

Standard 

Error

Estimate

1

Standard 

Error

Estimate

2

Standard 

Error

Degree of 

Confidence 

that Use 

Changed

3

Conversion 

Rate

4

Males 77% 2% 72% 1% 5% (S) 2% 99% 18%

in urban areas 76% 4% 67% 3% 9% (S) 4% 97% 27%

in suburban areas 78% 3% 73% 2% 5% (S) 3% 92% 19%

in rural areas 74% 3% 72% 2% 2% 4% 40% 7%

Females 84% 2% 79% 1% 5% 6% 58% 24%

in urban areas 85% 4% 78% 2% 7% (S) 4% 94% 32%

in suburban areas 86% 2% 81% 1% 5% (S) 2% 97% 26%

in rural areas 78% 4% 76% 4% 2% 5% 34% 8%

1

 An "H" or "L" indicates use that is statistically high or low in its category.

2

 An "S" indicates that use is statistically higher in 2003 with 90% confidence.

3

 The degree of statistical confidence in the assertion that use in 2003 was different than use in 2002.

4

 The conversion rate is the percentage reduction in safety belt nonuse.

Source: National Center for Statistics and Analysis, NHTSA, National Occupant Protection Use Survey

Table 9: Safety Belt Use by Gender and Geographic Region

Use in 2003 Use in 2002 2002-2003 Change

Motorist Group

Estimate

1

Standard 

Error

Estimate

1

Standard 

Error

Estimate

2

Standard 

Error

Degree of 

Confidence 

that Use 

Changed

3

Conversion 

Rate

4

Males 77% 2% 72% 1% 5% (S) 2% 99% 18%

in the Northeast 69% 3% 64% 2% 5% 4% 74% 14%

in the Midwest 71% 3% 69% 4% 2% 3% 46% 6%

in the South 79% 3% 73% 2% 6% (S) 3% 97% 22%

in the West 82% 5% 76% 3% 6% 5% 80% 25%

Females 84% 2% 79% 1% 5% 6% 58% 24%

in the Northeast 78% 2% 74% 2% 4% 3% 75% 15%

in the Midwest 80% 3% 80% 3% 0% 2% 0% 0%

in the South 89% 2% 80% 3% 9% (S) 2% 99% 45%

in the West 83% 9% 80% 2% 3% 7% 32% 15%

1

 An "H" or "L" indicates use that is statistically high or low in its category.

2

 An "S" indicates that use is statistically higher in 2003 with 90% confidence.

3

 The degree of statistical confidence in the assertion that use in 2003 was different than use in 2002.

4

 The conversion rate is the percentage reduction in safety belt nonuse.

Source: National Center for Statistics and Analysis, NHTSA, National Occupant Protection Use Survey
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 19

Table 10: Safety Belt Use by Gender and Ambient Enforcement Law

Use in 2003 Use in 2002 2002-2003 Change

Motorist Group

Estimate

1

Standard 

Error

Estimate

1

Standard 

Error

Estimate

2

Standard 

Error

Degree of 

Confidence 

that Use 

Changed

3

Conversion 

Rate

4

Males 77% 2% 72% 1% 5% (S) 2% 99% 18%

under primary laws 80% 3% 78% (H) 2% 2% 2% 68% 9%

under secondary laws 73% 3% 64% 2% 9% (S) 3% 99% 25%

Females 84% 2% 79% 1% 5% 6% 58% 24%

under primary laws 86% 4% 83% (H) 2% 3% 4% 61% 18%

under secondary laws 82% 2% 74% 1% 8% (S) 2% 99% 31%

1

 An "H" or "L" indicates use that is statistically high or low in its category.

2

 An "S" indicates that use is statistically higher in 2003 with 90% confidence.

3

 The degree of statistical confidence in the assertion that use in 2003 was different than use in 2002.

4

 The conversion rate is the percentage reduction in safety belt nonuse.

Source: National Center for Statistics and Analysis, NHTSA, National Occupant Protection Use Survey
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 20

Table 11: Safety Belt Use by Age and Urbanization

Use in 2003 Use in 2002 2002-2003 Change

Motorist Group

Estimate

1

Standard 

Error

Estimate

1

Standard 

Error

Estimate

2

Standard 

Error

Degree of 

Confidence 

that Use 

Changed

3

Conversion 

Rate

4

Ages 8-15 81% 6% 82% 3% -1% 2% 40% -6%

in urban areas 80% 9% 73% 10% 7% 15% 37% 26%

in suburban areas 83% 6% 83% 3% 0% 5% 0% 0%

in rural areas 74% 14% 82% 4% -8% 14% 44% -44%

Ages 16-24 75% 2% 69% 2% 6% (S) 2% 99% 19%

in urban areas 77% 4% 65% 4% 12% (S) 5% 98% 34%

in suburban areas 75% 4% 69% 2% 6% 4% 84% 19%

in rural areas 72% 3% 71% 3% 1% 4% 18% 3%

Ages 25-69 80% 2% 76% 1% 4% (S) 2% 95% 17%

in urban areas 79% 5% 72% 2% 7% 5% 87% 25%

in suburban areas 82% 2% 77% 2% 5% (S) 3% 95% 22%

in rural areas 76% 3% 73% 3% 3% 3% 66% 11%

Ages 70+ 81% 6% 82% 1% -1% 3% 29% -6%

in urban areas 82% 9% 79% 4% 3% 10% 24% 14%

in suburban areas 87% 3% 82% 2% 5% 3% 86% 28%

in rural areas 60% 22% 84% 3% -24% 21% 74% -150%

1

 An "H" or "L" indicates use that is statistically high or low in its category.

2

 An "S" indicates that use is statistically higher in 2003 with 90% confidence.

3

 The degree of statistical confidence in the assertion that use in 2003 was different than use in 2002.

4

 The conversion rate is the percentage reduction in safety belt nonuse.

Source: National Center for Statistics and Analysis, NHTSA, National Occupant Protection Use Survey
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 21

Table 12: Safety Belt Use by Age and Geographic Region

Use in 2003 Use in 2002 2002-2003 Change

Motorist Group

Estimate

1

Standard 

Error

Estimate

1

Standard 

Error

Estimate

2

Standard 

Error

Degree of 

Confidence 

that Use 

Changed

3

Conversion 

Rate

4

Ages 8-15 81% 6% 82% 3% -1% 2% 40% -6%

in the Northeast 88% 12% 93% 4% -5% 18% 22% -71%

in the Midwest 74% 14% 83% 6% -9% 9% 70% -53%

in the South 49% 12% 77% 17% -28% 6% 99% -122%

in the West 71% 15% 84% 7% -13% 11% 78% -81%

Ages 16-24 75% 2% 69% 2% 6% (S) 2% 99% 19%

in the Northeast 87% 4% 73% 7% 14% (S) 6% 99% 52%

in the Midwest 79% 7% 69% 4% 10% 7% 87% 32%

in the South 57% 9% 63% 3% -6% 3% 98% -16%

in the West 75% 8% 69% 3% 6% 7% 62% 19%

Ages 25-69 80% 2% 76% 1% 4% (S) 2% 95% 17%

in the Northeast 86% 7% 83% 2% 3% 4% 50% 18%

in the Midwest 84% 7% 79% 4% 5% (S) 2% 99% 24%

in the South 74% 7% 70% 4% 4% (S) 2% 97% 13%

in the West 82% 7% 78% 3% 4% 6% 51% 18%

Ages 70+ 81% 6% 82% 1% -1% 3% 29% -6%

in the Northeast 91% 7% 88% 4% 3% 7% 35% 25%

in the Midwest 75% 22% 87% 1% -12% 4% 99% -92%

in the South 33% 18% 71% 7% -38% 3% 99% -131%

in the West 67% 21% 85% 1% -18% 21% 61% -120%

1

 An "H" or "L" indicates use that is statistically high or low in its category.

2

 An "S" indicates that use is statistically higher in 2003 with 90% confidence.

3

 The degree of statistical confidence in the assertion that use in 2003 was different than use in 2002.

4

 The conversion rate is the percentage reduction in safety belt nonuse.

Source: National Center for Statistics and Analysis, NHTSA, National Occupant Protection Use Survey
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 22

Table 13: Safety Belt Use by Age and Ambient Enforcement Law

Use in 2003 Use in 2002 2002-2003 Change

Motorist Group

Estimate

1

Standard 

Error

Estimate

1

Standard 

Error

Estimate

2

Standard 

Error

Degree of 

Confidence 

that Use 

Changed

3

Conversion 

Rate

4

Ages 8-15 81% 6% 82% 3% -1% 2% 40% -6%

under primary laws 84% 10% 86% 3% -2% 8% 19% -14%

under secondary laws 77% 8% 76% 6% 1% 6% 13% 4%

Ages 16-24 75% 2% 69% 2% 6% (S) 2% 99% 19%

under primary laws 80% (H) 3% 73% (H) 2% 7% (S) 3% 96% 26%

under secondary laws 68% 5% 63% 3% 5% 4% 74% 14%

Ages 25-69 80% 2% 76% 1% 4% (S) 2% 95% 17%

under primary laws 82% 3% 80% (H) 0% 2% 2% 62% 10%

under secondary laws 77% 3% 69% 0% 8% (S) 2% 99% 26%

Ages 70+ 81% 6% 82% 1% -1% 3% 29% -6%

under primary laws 78% 11% 87% (H) 0% -9% 11% 59% -69%

under secondary laws 85% 4% 74% 0% 11% (S) 3% 99% 42%

1

 An "H" or "L" indicates use that is statistically high or low in its category.

2

 An "S" indicates that use is statistically higher in 2003 with 90% confidence.

3

 The degree of statistical confidence in the assertion that use in 2003 was different than use in 2002.

4

 The conversion rate is the percentage reduction in safety belt nonuse.

Source: National Center for Statistics and Analysis, NHTSA, National Occupant Protection Use Survey
 National Center for Statistics and Analysis, 400 Seventh St., S.W., Washington, DC 20590 23

6. References

Blincoe, L., Seay, A., Zaloshnja, E., Miller, T., Romano, E., Luchter, S., Spicer, R., The Economic Impact 

of Motor Vehicle Crashes, 2000, NHTSA Technical Report, DOT HS 809 446, May 2002

Block, A., 2000 Motor Vehicle Occupant Safety Survey, Volume 2: Seat Belt Report, NHTSA Technical 

Report, DOT HS 809 389, November 2001

Glassbrenner, D., Safety Belt Use in 2003, NHTSA Technical Report, DOT HS 809 646, September 2003

Glassbrenner, D., Safety Belt Use in 2002 – Use Rates in the States and Territories, NHTSA Research 

Note, DOT HS 809 587, May 2003

Glassbrenner, D., Safety Belt Use in 2002 – Demographic Characteristics, NHTSA Research Note, DOT 

HS 809 557, March 2003

Glassbrenner, D., Safety Belt and Helmet Use in 2002 – Overall Results, NHTSA Technical Report, DOT 

HS 809 500, September 2002

Hurd, T., USDOT Requires Improved Child Restraint Labels, NHTSA Press Release, NHTSA 63-02, 

October 2002

Hurd, T., Survey Finds Widespread Misuse of Air Bag On-Off Switches in Pickups, NHTSA Press 

Release, NHTSA 2-04, January 2004

Shinar, D., Schechtman, E., and Compton, R., Self-Report of Safe Driving Behaviors in Relationship to 

Sex, Age, Education and Income in the U.S. Adult Driving Population, Journal of Accident Analysis and 

Prevention, Vol. 33 (1), pp. 111-116, January 2001

Solomon, M., Nissen W., Preusser D., Occupant Protection Special Traffic Enforcement Program

Evaluation, NHTSA Technical Report, DOT HS 808 884, April 1999

Solomon, M., Ulmer, R., Preusser D., Evaluation of Click It or Ticket Model Programs, NHTSA

Technical Report, DOT HS 809 498, September 2002

Solomon, M., Chaudhary, N., Cosgrove, L., May 2003 Click It or Ticket Safety Belt Mobilization

Evaluation, NHTSA Technical Report, no DOT number available, November 2003

Traffic Safety Facts 2002 – Occupant Protection, NHTSA Fact Sheet, DOT HS 809 610, undated

Tyson, R., U.S. Transportation Secretary Mineta Launches Massive Law Enforcement Mobilization for 

Traffic Safety , NHTSA Press Release, NHTSA 19-03, May 2003
DOT HS 809 729

May 2004