Primary enforcement seat belt laws are effective even in the face of rising belt use rates

A recent systematic literature review found that primary enforcement laws are more effective at increasing seat belt use than secondary laws in the United States. This report re-examines the studies included in the systematic review to explore whether the benefits of a primary law differ based on: (1) the baseline seat belt use rate; or (2) whether or not the primary law replaces a secondary law. States that directly enacted primary laws showed larger increases in observed seat belt use (median increase of 33 percentage points). These laws were enacted in the mid-1980s, when baseline belt use rates were below 35%. Smaller, but substantial increases in belt use were observed in states that replaced secondary with primary laws (median increase of 14 percentage points). Baseline belt use rates in these states ranged from 47 to 73%. Primary safety belt laws can further increase seat belt use even in states with relatively high baseline levels of belt use.     

Getting Americans to buckle up: the efficacy of state seat belt laws

Annual state observed safety belt use rates over the period 1991–2001 are examined using time-series cross-section regression analysis. It was found that seat belt laws are associated with higher use rates and that the enforcement provision matters. Primary states experience belt use rates that on average are 9.1 percentage points higher than their secondary counterparts. In addition, the level of the fine imposed by statute has an effect on safety belt use apart from that attributable to the enforcement provision. The current median fine of $25 is associated with an additional 3.8 percentage points increase in belt use. To further increase safety belt use, it is recommended that states adopt primary enforcement and impose fines of at least $50 for violating a seat belt law.     

Seat belt use among 13-15 year olds in primary and secondary enforcement law states

CONTEXT: Coverage and enforcement provisions of safety belt use laws vary by state. Most laws cover drivers and passengers age 16 and above. "Primary" enforcement laws allow police to stop and ticket a motorist for a safety belt law violation. With "secondary" enforcement laws, ticketing can only occur in the presence of another traffic infraction. Given the lower rates of restraint use among teen drivers and their passengers, the effect of primary enforcement laws on the restraint use of young teen passengers is of particular interest. OBJECTIVE: To compare restraint use by 13-15 year olds passengers in motor vehicle crashes in states with primary versus secondary enforcement safety belt laws. METHODS: Cross-sectional study of 3953 crashes involving 5372 children, representing 54,226 children aged 13-15 years in 41,198 crashes of insured vehicles in 16 states and Washington, DC between December 1, 1998 and December 31, 2004, with data collected via insurance claims records and a telephone survey. RESULTS: Non-use of restraints by 13-15 year olds was 7.2% (95% CI 4.3-10.1%) greater in secondary enforcement states (10.8%) as compared to states with primary enforcement laws (3.6%). After controlling for driver's age and restraint status and the seating row of the occupant, a 13-15 year olds was over twice as likely to be unrestrained in a secondary enforcement state as compared to a primary enforcement state (adjusted RR=2.2, 95% CI 1.5-3.1). CONCLUSIONS: States considering primary enforcement provisions to their restraint laws should consider the potential benefits these laws may have to all occupants in the vehicle, particularly young adolescents who are nearing driving age.     

The effects of standard enforcement on Michigan safety belt use

The purpose of this study was to assess the effects of standard enforcement legislation on safety belt use in Michigan through a series of seven statewide direct observation surveys. A secondary purpose of the study was to compare the results in Michigan to the results in other states that have changed the provision of their mandatory safety belt use law from secondary to standard enforcement. The study found that standard enforcement has been effective in increasing safety belt use in Michigan. Immediately following the implementation of standard enforcement, Michigan's belt use rate increased to 83.5%, 13.4 percentage points higher than the highest rate previously observed. One year after the change, safety belt use in Michigan was still nearly 10 percentage points greater than the highest observed rate before standard enforcement legislation was enacted. Results indicated that safety belt use decreased slightly in the year following the implementation of standard enforcement. This appears to be an overall trend across all observed groups, and not due to any single demographic category. The results also suggest that standard enforcement legislation appears to have a greater effect on groups with historically low belt use, such as young people, males, passengers, and Black/African–Americans. When compared with other states that have made the change from secondary to standard enforcement, the increase in the safety belt use rate in Michigan was comparable to the increase seen in states with relatively high safety belt use prior to standard enforcement. However, states that had low safety belt use rates prior to adopting standard enforcement legislation observed a larger percentage point increase in the year following their change to standard enforcement.     

Seat belt use among African Americans,Hispanics, and Whites

OBJECTIVES: This study investigated seat belt use among White, Black, and Hispanic drivers, in cities in which standard enforcement of the belt use law is permitted (primary enforcement) and in cities in which a motorist has to be first cited for another offense (secondary enforcement). Socioeconomic and gender differences in belt use were also studied. METHODS: Belt use observations were obtained at gas stations in Boston, Chicago, Houston, and New York City. In short interviews with drivers, information on race/ethnicity and education was obtained. RESULTS: Belt use was higher in primary enforcement cities, among women, and among those with at least a college degree. In primary law cities there were no clear differences in belt use by race/ethnicity; in secondary cities African Americans were less likely than Whites or Hispanics to be belted, among populations both with and without college degrees. This is consistent with data from other studies indicating that African Americans are more sensitive than Whites to the enforcement of primary laws and are more likely to increase belt use when states shift from secondary to primary. There has been no evidence of enforcement bias against African Americans--increases in citations generally have been greater among Whites than African Americans once primary enforcement is implemented. CONCLUSIONS: More widespread application of primary laws--standard throughout the world but in only 17 US states and the District of Columbia--would increase belt use for all drivers, especially African Americans.     

Patterns of safety belt usage following introduction of a safety belt wearing law

The paper reviews the process of enacting a safety belt wearing law in Israel, and studies the impact it has had on belt usage and on casualty reductions. Safety belt legislation in Israel had several unique features in that, on the one hand, all passenger vehicles were retrofitted with safety belts, but, on the other hand, it exempted drivers and front-seat passengers of pre-1969 model vehicles from the compulsory use of belts. Also, the legislation applied only to the use of belts on interurban roads. Repeated counts of safety belt usage, before and after the implementation of the law, provided strong evidence for the efficacy of the legislative act as such. Usage rates rose from an average of 6% to upward of 70%. There was a marked carryover effect of the law on belt wearing rates on urban roads and on the use by drivers of pre-1969 model cars. However, this effect diminished with time. Results of a questionnaire survey provided further evidence for the general acceptance of the law by the public. Only a small minority of drivers completely rejected the use of safety belts. A comparison with data from other countries shows that the impact of a compulsory safety belt wearing law on safety belt usage and on casualty reduction is a universal phenomenon. This fact should encourage researchers, legislators and adminstrators in jurisdictions which are still deliberating the value of mandatory safety belt legislation. On the basis of the trends in fatalities and casualties to car drivers and passengers on urban roads during the two and one-half year period following the introduction of the seat belt law, it is estimated that a reduction of 42% in car fatalities and 44% in car passengers occurred on interurban roads during those two and one-half years. The corresponding reductions in casualties were 18% and eight percent respectively.     

Do states upgrading to primary enforcement of safety belt laws experience increased daytime and nighttime belt use?

As of 1 January 2007, 26 states and the District of Columbia have enacted primary enforcement of their safety belt laws, which allows law enforcement to stop motorists and cite them solely when they observe a vehicle occupant who is not wearing a safety belt. Interrupted time series analyses were used to determine whether six states which upgraded to primary enforcement laws experienced changes in nighttime (9:00 p.m. to 4:59 a.m.) and daytime (5:00 a.m. to 8:59 p.m.) safety belt use based on proxy estimates from fatal crash-involved vehicle occupants. Nighttime and daytime safety belt use increased in five of the six states after the primary enforcement laws were enacted. Because the methods used in these analyses reduced the likelihood that these increases resulted from preexisting secular trends towards increased belt use, the results provide strong support that upgrading from secondary to primary enforcement increases occupant safety belt use during both daytime and nighttime periods.     

The effect of changing from secondary to primary safety belt enforcement on police harassment

The purpose of the study was to investigate whether changing Michigan's safety belt law from secondary to primary (standard) enforcement resulted in police harassment. The study investigated safety-belt-enforcement-related harassment by considering three measures: citizen complaints arising from enforcement of the safety belt law; citation over-representation, that is, a statistical determination of whether certain groups received more citations than would be expected based upon their presence in the driving population and their rate of violating the safety belt use law; and self-reported harassment among the population of people who receive safety belt citations. Safety-belt-related harassment complaints were very uncommon both before and after primary enforcement. Implementation of primary enforcement did not lead to an increase in citation over-representation, and, therefore, safety-belt-related harassment by sex, race, or age. The vast majority of people receiving safety belt citations reported officer behavior as professional and did not feel that they were singled out for their citation. However, a sizeable minority of Blacks and young people report perceptions of safety-belt-related harassment. Results suggest that states with secondary enforcement should continue their efforts to change to primary enforcement, but should also make a strong effort to educate both law enforcement and the public about the harassment issue.     

Geographic and sociodemographic variation in self-reported seat belt use in the United States

Background

With new data available, we sought to update existing literature on the prevalence of self-reported seat belt use by state, region, and rural/urban status and to estimate the strength of the association between seat belt use and rural/urban status adjusted for type of seat belt law and several other factors.

Methods

We examined data on self-reported use of seat belts from 50 states, the District of Columbia, and three territories using the 2008 Behavioral Risk Factor Surveillance System, a state-based random-digit-dialed telephone survey (n = 406,552). Reported seat belt use was assessed by state, U.S. Census regions, and U.S. Department of Agriculture (USDA) rural/urban continuum codes.

Results

Overall, 85% of adults in the United States reported they always used seat belts. Regionally, the West had the highest prevalence of persons who reported that they always wear seat belts (89.6%) and the Midwest had the lowest (80.4%). States with primary seat belt laws had the highest prevalence of reported seat belt use, compared with states with secondary or no laws. After adjusting for various sociodemographic characteristics, body mass index, and type of seat belt law, persons in the most densely populated metropolitan areas were significantly more likely to report always wearing seat belts than those in most sparsely populated rural areas (adjusted odds ratio = 2.9).

Conclusion

Our findings reinforce the evidence that primary enforcement seat belt laws are effective for increasing seat belt use, and suggest that upgrading to primary enforcement laws will be an important strategy for reducing crash-related fatalities in rural areas.     

Seat belt utilization in Saudi Arabia and its impact on road accident injuries

Most industrialized countries and many developing countries have passed laws that require the use of seat belts in motor vehicles. It is widely believed that seat belt use is an effective way to reduce road accident fatalities and injuries. Saudi Arabia joined these countries when it enacted a similar law on 5 December 2000 making seat belt use compulsory for all drivers and front-seat passengers. This study measures seat belt use rate and its impact on the number of road accident injuries during the first few months that followed the enactment of the law. It also investigates drivers' behaviour and personal characteristics and their relationship with using seat belts by using a questionnaire specially prepared for this purpose. Results show that seat belt use rate in two Riyadh suburbs were 33% and 87%, respectively, for drivers and 4% and 41%, respectively, for front-seat passengers (FSP's). Such belt use rates are considered low yet encouraging when compared with use rates before enacting the law. Results also show that there was a significant drop in certain types of injuries due to traffic accidents after the enactment of the seat belt law. Questionnaire results show that certain personal characteristics were correlated with seat belt use rate. Finally, implications of these findings in terms of future plans for improving traffic safety are discussed.     

Shoulder belt use in four states with belt use laws

Shoulder belt use was observed before and after belt use laws went into effect in New York, New Jersey, Illinois, and Texas. There were large increases in belt use rates in each state in the first month the laws were enforced. In the three states in which post-law observations were made more than once, belt use declined from the levels seen in the first month; rates generally dropped to less than 50 percent. This pattern of decline from initial use rates has also been found in other jurisdictions around the world. Combined enforcement and publicity campaigns have been shown to be capable of reversing this trend and to increase use rates to 65 percent or more. Such campaigns will be needed to maximize the effect of seat belt use laws in the United States.     

Traffic safety and the switch to a primary seat belt law: the California experience

This study explores whether the change of an existing seat belt law from secondary to primary enforcement enhances traffic safety. In particular, we examine traffic fatalities and injuries in California from 1988 to 1997. During the first half of this period, California law provided for secondary enforcement of its mandatory seat belt law, but in 1993 it upgraded the law to primary enforcement. Controlling for the number of motor vehicle collisions, a Box–Tiao intervention analysis of the time series is used to compare the monthly fatalities and injuries before and after the change in the enforcement provision. The results show that California experienced an improvement in traffic safety in terms of a significant reduction in injuries, but the change in enforcement provision had no statistically significant impact on fatalities.     

Increasing safety belt use in a secondary enforcement state: evaluation of a three-county special enforcement program.

Special enforcement programs to increase belt use present a unique challenge in states with secondary enforcement laws. This paper reports findings from an evaluation of a combined public information and education/enforcement program to increase restraint use along a highly traveled corridor in three Michigan counties. This program (US-31 SAVE) was successful in increasing belt use at least temporarily along the special enforcement corridor. Observed belt use increased from a baseline rate of 56.7% to 65.1% during the program before slipping slightly to 62.7% after the intensive enforcement and PI&E declined (all differences significant at p less than .05). This paper details program and evaluation activities and suggests future research needs to better understand the most effective mix of public information and enforcement efforts in states with secondary belt use laws.     

Trends in driver and front-right passenger safety belt use in Michigan: 1984-1998

As part of Michigan’s effort to track trends in safety belt use within the state over time, the University of Michigan Transportation Research Institute conducted 20 statewide surveys of safety belt use between 1984 and 1998. Results indicate that Michigan safety belt use trends for drivers and front-right passengers are similar to other statewide and national trends. Belt use in Michigan increased dramatically immediately after the state implemented its mandatory belt use law (secondary enforcement) followed by a smaller decline that leveled off at a rate more than 20 percentage points higher than before the law. Belt use was consistently higher among drivers than front-right passengers, older than younger front-outboard occupants, females than males, and front-outboard occupants exiting freeways than those stopped at local intersections. Examination of belt use trends in Michigan provides useful information for continued efforts to increase belt use in our state and for all states interested in meeting national goals for safety belt use for the year 2000 and beyond.     

Effects of a mandatory safety belt law on hospital admissions

Although the effectiveness of automobile safety belts in reducing risk of serious injury in traffic crashes is well documented, safety belt use in many U.S. jurisdictions remains low. Michigan's mandatory safety belt law for front-seat occupants, implemented in July 1985, is one of 34 similar laws in the United States intended to increase belt use and reduce crash-related injuries. Using time-series intervention analyses of data from 14 hospitals throughout the state, we found a 19% reduction in the rate of admitted patients for all automobile occupant injuries and a 20% reduction in the rate of admitted patients with extremity injuries following implementation of the safety belt law. The utility of hospital data for the evaluation of interventions like the safety belt law reinforce the importance of consistently recording E-codes for all injury patients.     

An investigation of state population characteristics that moderate the relationship of state seat belt law and use in the United States

Objectives

Primary enforcement laws have been shown to be effective methods for increasing seat belt use at the state level.

Method

This study investigates state differences in the effectiveness of primary enforcement laws by assessing whether a state's academic achievement, health ranking, economic prosperity, violent crime rates, government effectiveness, gender distribution, or proportion of rural roads moderate the relationship between those laws and seat belt compliance rates.

Results

Aggregate state-level academic achievement, health ranking, government effectiveness, and proportion of rural roads uniquely moderated the seat belt use differences between primary and secondary enforcement states.

Conclusions

This evidence suggests that cultural, social, and demographic differences among regions may be important factors in explaining state-level differences in the effectiveness of primary enforcement of seat belt laws.     

The effect of population safety belt usage rates on motor vehicle-related fatalities.

The effectiveness of safety belt usage in reducing mortality and morbidity among traffic crash victims has been well established. Population safety belt usage rates have been increasing from 11% in 1980 to 68% in 1995, as measured by observational surveys sponsored by the National Highway Traffic Safety Administration (NHTSA). Safety incentive grants from NHTSA to the States with higher than average usage rates are expected to total $500 million during 1999-2003. In this paper, longitudinal annual motor vehicle-related fatality levels are analyzed by state to estimate the effect of the population safety belt usage rate on traffic fatality rates in the presence of known confounders such as alcohol use and youthful drivers. Consideration of alternative models applied to 14 years of data shows that the population safety belt usage rate (at least, at the current rates) is associated with little or no effect on reducing fatality rates. On the other hand, higher safety belt usage rates arising from states with primary enforcement laws tend to suggest reductions in fatality rates. Such results call into question the NHTSA policy of basing incentive programs on overall safety belt usage rates.     

Results of a seat belt use law enforcement and publicity campaign in Elmira, New York

In New York and other states in which seat belt use laws went into effect in the mid-1980s, belt use rates surged initially, then declined. This pattern of belt use also occurred in Canadian provinces that enacted laws in the mid-1970s; special enforcement programs reversed this trend. In late 1985 a three-week enforcement and publicity program was conducted in Elmira, New York. Belt use rates in Elmira were 49 percent before the program, 77 percent right after, and 66 percent two months later. In Glens Falls, a comparison city without a program, belt use declined from 43 percent to 37 percent during this interval. In a telephone survey after the campaign, Elmira respondents were more likely to say the belt use law was being strictly enforced and were more favorable toward it, compared to Glens Falls respondents. These data indicate that enforcement/publicity programs are an important and feasible method for increasing compliance with belt use laws.     

Attitudes of commercial motor vehicle drivers towards safety belts

Despite the fact that Hawaii has one of the highest seat belt use rates for passenger vehicles in the United States, and has had a mandatory seat belt use law since the 1980s, studies have shown that commercial motor vehicles (CMV) seat belt use rates are low. To better understand this phenomenon, a comprehensive survey of commercial vehicle drivers was conducted in Hawaii to ascertain attitudes and self-reported behaviors regarding seat belt use. A total of 791 drivers responded to a written questionnaire implemented at weigh stations and distributed to various trucking firms and transport centers. Approximately 67% reported that they use seat belts “always” when driving a CMV (commercial motor vehicle), yet when asked how often do other CMV drivers use seat belts, only 31% responded “always.” Interestingly, 86% of these same drivers reported that they use seat belts “always” when driving a personal vehicle. The major reason cited for non-use of belts was “frequent stops/inconvenience” (29%), and “not safety conscious” (23%). Notably, the self-reported use of safety belts is highest among operators of vans (88% said “always”), followed by buses (87% said “always”) and lowest among truck drivers (only 60% said “always”). In this paper, some of the differences between self-reported users and non-users are explored and a multivariate logit model was developed to predict the odds of belt use as a function of various factors.