Predicting seat belt use in fatal motor vehicle crashes from observation surveys of belt use

Determinants of seat belt use: A regression analysis with FARS data corrected for self-selection

INTRODUCTION

We develop a methodology to use FARS data as an alternative to NOPUS in estimating seat belt usage. The advantages of using FARS over NOPUS are that (i) FARS is broader because it contains more variables relevant for policy analysis, (ii) FARS allows for easy multivariate regression analysis, and finally, (iii) FARS data is more cost-effective.

METHODOLOGY

We apply a binary logit model in our analysis to determine the likelihood of seat belt usage given various occupant, vehicle, and built environment characteristics. Using FARS data, we derive coefficient estimates for categories such as vehicle occupants' age and night time seat belt use that observational surveys like NOPUS cannot easily provide.

RESULTS

Our results indicate that policies should focus on passengers (as opposed to drivers), male and young vehicle occupants, and that law enforcement should focus on pick-up trucks, rural roads, and nights. We find evidence that primary seat belt laws are effective.

CONCLUSIONS

Although this is primarily a methodological paper, we present and discuss our results in the context of public policy so that our findings are relevant for road safety practitioners, researchers, and policymakers.

Preventive Effects of Seat Belt on Clinical Outcomes for Road Traffic Injuries

Proper seat belt use saves lives; however, the use rate decreased in Korea. This study aimed to measure the magnitude of the preventive effect of seat belt on case-fatality across drivers and passengers. We used the Emergency Department based Injury In-depth Surveillance (EDIIS) database from 17 EDs between 2011 and 2012. All of adult injured patients from road traffic injuries (RTI) in-vehicle of less than 10-seat van were eligible, excluding cases with unknown seat belt use and outcomes. Primary and secondary endpoints were in-hospital mortality and intracranial injury. We calculated adjusted odds ratios (AORs) of seat belt use and driving status for study outcomes adjusting for potential confounders. Among 23,698 eligible patients, 15,304 (64.6%) wore seat belts. Driver, middle aged (30-44 yr), male, daytime injured patients were more likely to use seat belts (all P < 0.001). In terms of clinical outcome, no seat belt group had higher proportions of case-fatality and intracranial injury compared to seat belt group (both P < 0.001). Compared to seat belt group, AORs (95% CIs) of no seat belt group were 10.43 (7.75-14.04) for case-fatality and 2.68 (2.25-3.19) for intracranial injury respectively. In the interaction model, AORs (95% CIs) of no seat belt use for case-fatality were 11.71 (8.45-16.22) in drivers and 5.52 (2.83-14.76) in non-driving passengers, respectively. Wearing seat belt has significantly preventive effects on case-fatality and intracranial injury. Public health efforts to increase seat belt use are needed to reduce health burden from RTIs.

Self-reported and observed seat belt use--A case study: Bosnia and Herzegovina

The issue of seat belt use in middle- and low-income countries is strongly evident and has as a result higher rates of fatalities and seriously injured on the roads. The first systematic field research of the seat belt use while driving was carried out in Bosnia and Herzegovina, in 2011-2012. Research methodology consisted of two mutually conditioned parts (observation and self-reported behavior). Specific features of the methodology used are in the relationship between the observed and interviewed drivers which enabled the analysis of their observed and self-reported behavior while driving. The logistic regression method was used in this work to make the analysis of the influence of personal human characteristics (gender, age, education, exposure) and vehicles' characteristics (age) on the observed and self-reported driving behavior, from the point of view of seat belt use while driving. The influence of the listed factors on driving behavior, depending on road type (urban or rural), was given special attention in the analysis. The paper shows that certain factors do not have the same impact on driving behavior, in various conditions. Based on results from this study, it will be possible to define certain critical groups of road users and the way in which they must be addressed in order to increase the seat belt wearing rate.

Killer crashes: fatal road traffic accidents in the UK

Road traffic accidents are responsible for over 3000 deaths per year in the UK, according to Department for Transport (2004a) figures. Although progress is being made in a number of areas, vehicle occupant fatalities have not been falling in line with casualty reduction targets for the year 2010. A sample of 1185 fatal vehicle occupant cases was considered, from ten UK police forces, from the years 1994-2005 inclusive. The main findings were: (1) over 65% of the accidents examined involved driving at excessive speed, a driver in excess of the legal alcohol limit, or the failure to wear a seat belt by a fatality, or some combination of these. (2) Young drivers have the great majority of their accidents by losing control on bends or curves, typically at night in rural areas and/or while driving for 'leisure' purposes. These accidents show high levels of speeding, alcohol involvement and recklessness. (3) Older drivers had fewer accidents, but those fatalities they were involved in tended to involve misjudgement and perceptual errors in 'right of way' collisions, typically in the daytime on rural rather than urban roads. Blameworthy right of way errors were notably high for drivers aged over 65 years, as a proportion of total fatal accidents in that age group.

Correcting sample selection in FARS data to estimate seatbelt use

INTRODUCTION

In this paper, we show that FARS data can be a comparable alternative to observational NOPUS data in estimating seat belt use in the United States once we correct for sample selection bias.

RESULTS

Based on assumptions of independence for seatbelt choice, we establish a lower and upper bound for seatbelt usage rates, and find that once we correct for sample selection bias, the seatbelt usage estimates from the corrected FARS emerge at least as a comparable alternative to NOPUS estimates.

IMPACT ON INDUSTRY

This implies that researchers can use corrected FARS to complement NOPUS, thus being able to utilize the rich cross-sectional details available in FARS data to analyze various relevant research questions.

Analysis of teenage seat belt use: from the 2007 Missouri high school seat belt survey

INTRODUCTION

This study analyzed high school teenagers' seat belt use based on the observational surveys of more than 15,000 teenagers at 150 schools and was conducted in the state of Missouri, U.S., in 2007. Since fatal car accidents involving high school teenagers are disproportionately high, and increased seat belt use saves lives in what would otherwise be fatal accidents, it is imperative that teenagers' safety be protected through an increase in use.

METHOD

This study investigated various personal, vehicle, school, and locational factors associated with high school teenagers' seat belt use. Descriptive and binary logit analyses were conducted.

RESULTS

We find that low seat belt use is associated with males, African-Americans, pick-up trucks, accompanying occupants, weekends, inclement driving conditions, small size of school, lower socio-economic status, and rural county school locations. Several factors influencing teenage seat belt use are quite similar to those affecting adult seat belt use, in addition to certain risky behaviors to which teenagers are prone, supporting the importance of early intervention.

CONCLUSIONS

Programs in schools, the adoption of primary seat belt laws, GDL provisions requiring seat belt use, targeted education and campaign efforts for African-American teenagers, seat belt reminder systems, and more resources for rural counties on safety education and enforcement may help increase seat belt use in this vulnerable age group, though other research questions are implied.

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.

Mathematical models assuming selective recruitment fitted to data for driver mortality and seat belt use in Japan

Previous research has indicated that unbelted drivers are at higher risk of involvement in fatal crashes than belted drivers, suggesting selective recruitment that high-risk drivers are unlikely to become belt users. However, how the risk of involvement in fatal crashes among unbelted drivers varies according to the level of seat belt use among general drivers has yet to be clearly quantified. We, therefore, developed mathematical models describing the risk of fatal crashes in relation to seat belt use among the general public, and explored how these models fitted to changes in driver mortality and changes in observed seat belt use using Japanese data. Mortality data between 1979 and 1994 were obtained from vital statistics, and mortality data in the daytime and nighttime between 1980 and 2001 and belt use data between 1979 and 2001 were obtained from the National Police Agency. Regardless of the data set analyzed, exponential models, assuming that high-risk drivers would gradually become belt users in order of increasing risk as seat belt use among general motorists reached high levels, showed the best fit. Our models provide an insight into behavioral changes among high-risk drivers and support the selective recruitment hypothesis.

Effect on fatality risk of changing from secondary to primary seat belt enforcement

BACKGROUND

Most seat belt use laws originally passed in the United States contained language restricting enforcement to drivers already stopped for some other reason. States that have since removed this secondary enforcement restriction have reported increased seat belt use. The purpose of the present study was to estimate the effect of these law changes on driver fatality rates.

METHOD

Trends in passenger vehicle driver death rates per billion miles traveled were compared for 10 states that changed from secondary to primary seat belt enforcement and 14 states that remained with secondary enforcement.

RESULTS

After accounting for possible economic effects and other general time trends, the change from secondary to primary enforcement was found to reduce annual passenger vehicle driver death rates by an estimated 7% (95% confidence limits 3.0-10.9).

CONCLUSION

The majority of U.S. states still have secondary enforcement laws. If these remaining secondary laws were amended, an estimated 696 deaths per year could be prevented.

Ninety five percent: an evaluation of law, policy, and programs to promote seat belt use in Washington state

Seat belt use in Washington state was 83% in 2001. In 2002, a series of law, policy, and program initiatives coalesced to produce a dramatic increase in seat belt use. Washington enacted a primary enforcement seat belt, the Chief of the Washington State Patrol made safety belt enforcement one of the core missions of that agency, and Washington participated in the national Memorial Day Click It or Ticket program during May 2002 and continued the program into 2003. Evaluation of these initiatives was accomplished through observation surveys of seat belt use, analysis of seat belt violation data, and analysis of data on traffic deaths of motor vehicle occupants. The major findings were that there was a two- to three-fold increase in enforcement of the seat belt law, belt use rates increased to 93% in 2002 and again to 95% in 2003, and motor-vehicle occupant fatalities decreased by 13%. IMPACT ON PRACTICE AND POLICY: The primary seat belt law and Click It or Ticket program activities were critical factors in increasing belt use in Washington state. Media and enforcement programs targeting seat belt use can be very effective in raising the belt use rate, but a long-term commitment to continuation of these program activities is essential. Other states implementing new primary seat belt laws should consider delivering a Click It or Ticket campaign prior to the effective date of the primary law and continuing these activities during subsequent months and years.

Seatbelt legislation in Japan: high risk driver mortality and seatbelt use

OBJECTIVES

To clarify why seatbelt legislation did not achieve the expected reduction in mortality in Japan. LOCATION AND BACKGROUND: Seatbelt legislation was enacted in Japan in September 1985 and penalties were introduced in November 1986.

METHODS

The driver deaths per vehicle km traveled (D/VKT) were calculated to adjust for changes in traffic volume. Decreases in D/VKT were compared with the reduction expected after legislation. The association between percentage changes of driver D/VKT, seatbelt use rate, and seatbelt non-use rate were explored. Deaths of passengers, pedestrians, and cyclists were also examined. Mortality data were obtained from vital statistics, traffic volume figures from the Ministry of Land, Infrastructure, and Transport, and seatbelt use rates from the National Police Agency.

RESULTS

Although the decrease in D/VKT after the law was enforced was larger than the absolute number of deaths, it was far less than predicted. The percentage decrease in seatbelt non-use rate showed the strongest correlation with the percentage decrease in driver mortality. Mortality did not increase among other road users after the law was enacted.

CONCLUSION

Accurate evaluation of the effect of seatbelt legislation must take into account changes in traffic volume. The selective recruitment hypothesis-that high risk drivers were less responsive to seatbelt legislation-fits well with the findings. There was no conclusive evidence supporting risk compensation-that is, an increase in injuries among other road users.