1 table, 1 figure omitted
Motor-vehicle crashes are the leading cause of death among persons aged
1-34 years in the United States.1 Safety
belts are the single most effective means of reducing crash-related deaths.2 State laws have had a critical role in increasing
belt use. As of December 2003, the District of Columbia (DC), 20 states, and
three U.S. territories* had primary laws (i.e., primary enforcement safety-belt
laws), which allow police to stop a motorist and issue a citation solely for
being unbelted. Another 29 states had secondary laws, which allow police to
issue a safety-belt citation only after stopping a motorist for a different
violation. Primary laws are more effective than secondary laws for increasing
safety-belt use and reducing traffic fatalities.3 To
assess safety-belt use among U.S. states and territories with and without
primary laws, CDC analyzed data from the 2002 Behavioral Risk Factor Surveillance
System (BRFSS) survey. This report summarizes the results of that analysis,
which indicated that the prevalence of self-reported safety-belt use was higher
among states with primary laws (85.3%) than among states with secondary laws
(74.4%). To reduce deaths from motor-vehicle crashes, states should consider
enactment of primary laws.
In 2002, all 50 states, DC, Guam, Puerto Rico, and the U.S. Virgin Islands
(USVI) participated in BRFSS, a state-based, random-digit–dialed telephone
survey of the noninstitutionalized, civilian U.S. population aged ≥18 years.
Prevalence estimates were weighted to represent the state and territorial
populations. SUDAAN was used to account for the complex sampling design.
Safety-belt use was estimated on the basis of responses to the following
question: "How often do you use safety belts when you drive or ride in a car?"
Response options were "always," "nearly always," "sometimes," "seldom," "never
wear a belt," or "never drive or ride in cars." Respondents who never drove
or rode in cars, refused to respond, or responded "don't know" (n = 807) were
excluded from all analyses. Sample size for this study was 244,563; median
response rate was 58.6% (range: 42.2%-82.6%). Jurisdictions were identified
as having either primary or secondary safety-belt laws in effect during 2002.
Washington enacted a primary law in July 2002 and was classified as a primary-law
state for analysis; New Hampshire has no safety-belt law that applies to persons
aged ≥18 years but was classified as a secondary-law state for analysis.
Among the 50 states and DC, prevalence of always using a safety belt
ranged from 52.4% in North Dakota to 92.2% in California. Safety-belt use
was higher in states with primary laws (85.3%; 95% confidence interval [CI]
= 84.9%-85.7%) than in states with secondary laws (74.4%; 95% CI = 74.1%-74.8%).
In addition, the prevalence of never using a safety belt among states with
secondary laws (4.1%; 95% CI = 3.9%-4.3%) was more than double the prevalence
among states with primary laws (1.8%; 95% CI = 1.7%-2.0%). Among territories,
the prevalence of always using safety belts was 85.7% in Guam, 92.6% in Puerto
Rico, and 77.2% in USVI. A total of 18 states, DC, and the three territories
had primary laws during the study period; 17 of these 22 jurisdictions reported
safety-belt use of ≥80%. All 12 states with <70% belt use had secondary
LF Beck, MPH, KA Mack, PhD, RA Shults, PhD, Div of Unintentional Injury
Prevention, National Center for Injury Prevention and Control, CDC.
Increasing the use of safety belts could substantially reduce deaths
from motor-vehicle crashes in the United States, where safety-belt use ranks
among the lowest of high-income countries (i.e., countries with annual gross
national product of ≥$9,206 per capita).4 Residents
of states with secondary laws were less likely to use safety belts than residents
of states with primary laws, a finding supported by observational studies
(i.e., studies in which belt use is observed directly by an independent data
collector).5 In contrast to BRFSS, observational
studies provide information about safety-belt use for a single occasion and
for drivers and front-seat passengers only. In 2002, the prevalence of observed
safety-belt use was 69% in states with secondary laws and 80% in states with
The findings in this report are subject to at least three limitations.
First, BRFSS excludes households without telephones; however, because only
an estimated 2.4% of U.S. homes are without telephones, this limitation should
have minimal impact on the findings. Second, the BRFSS sample is limited to
noninstitutionalized, civilian adults and might not be representative of safety-belt
use among youths, institutionalized persons, or military personnel. Finally,
the data are self-reported, and social-desirability bias might result in overestimates
of safety-belt use.
In April 1997, the U.S. Department of Transportation recommended that
all states enact and actively enforce primary enforcement safety-belt laws.6 Since those recommendations were issued, only eight
additional states have enacted primary laws. As of December 2003, a total
of 29 states had secondary laws, and one state (New Hampshire) had no law
mandating safety-belt use by adults.
Perceived public opposition to primary laws is a potential barrier to
their implementation. Infringement on personal freedom and the potential for
differential enforcement on the basis of race/ethnicity are the concerns voiced
most frequently.7 However, a national survey
conducted in 2000 indicated that 61% of U.S. residents supported primary laws,
with support higher in states with primary laws (70%) than in states with
secondary laws (53%).8 In response to concerns
about differential enforcement, certain states have added anti-harassment
language to their laws to reduce the potential for discrimination7; available evidence does not demonstrate problems
with differential enforcement.9
On the basis of systematic reviews of published studies, the Task Force
on Community Preventive Services issues recommendations on population-based
interventions to promote health and prevent disease, injury, disability, and
premature death. The Task Force recommends the use of primary laws because
of strong evidence demonstrating that they have a greater impact than secondary
laws.10 The Task Force also recommends high-visibility
enforcement of the laws (e.g., safety-belt checkpoints) to further increase
safety-belt use.10 The findings in this
report indicate that differences in safety-belt use persist on the basis of
the type of law in effect in the state. States should consider primary-enforcement
safety-belt laws as an effective strategy to increase safety-belt use and
decrease serious injuries and deaths associated with motor-vehicle crashes.
This report is based on data contributed by state BRFSS coordinators.
*Alabama, California, Connecticut, Delaware, Georgia, Hawaii, Illinois,
Indiana, Iowa, Louisiana, Maryland, Michigan, New Jersey, New Mexico, New
York, North Carolina, Oklahoma, Oregon, Texas, Washington; Guam, Puerto Rico,
and U.S. Virgin Islands.
Impact of Primary Laws on Adult Use of Safety Belts—United States, 2002. JAMA. 2004;291(19):2310-2311. doi:10.1001/jama.291.19.2310