Observed and self-reported seat belt wearing as related to prior traffic accidents and convictions

Driving Safety

Driving is a common and hazardous activity that is a prominent cause of death worldwide. Driver behavior represents a predominant cause, contributing to over 90% of crashes. In this review, I will focus on how driver behavior influences driving safety by describing the types of crashes and their general causes, the driving process, the perceptual and cognitive characteristics of drivers, and driver types and impairments. Evidence from each of these perspectives suggests that breakdowns of a multilevel control process are the fundamental factors that undermine driving safety. Drivers adapt and drive safely in a broad range of situations but fail when expectations are violated or when feedback is inadequate. The review concludes by considering driving safety from a societal risk management perspective.

Underutilization of occupant restraint systems in motor vehicle injury crashes: A quantitative analysis from Qatar

INTRODUCTION

Restraint systems (seat belts and airbags) are important tools that improve vehicle occupant safety during motor vehicle crashes (MVCs). We aimed to identify the pattern and impact of the utilization of passenger restraint systems on the outcomes of MVC victims in Qatar.

METHODS

A retrospective study was conducted for all admitted patients who sustained MVC-related injuries between March 2011 and March 2014 inclusive.

RESULTS

Out of 2,730 road traffic injury cases, 1,830 (67%) sustained MVC-related injuries, of whom 88% were young males, 70% were expatriates, and 53% were drivers. The use of seat belts and airbags was documented in 26 and 2.5% of cases, respectively. Unrestrained passengers had greater injury severity scores, longer hospital stays, and higher rates of pneumonia and mortality compared to restrained passengers (P = .001 for all). There were 311 (17%) ejected cases. Seat belt use was significantly lower and the mortality rate was 3-fold higher in the ejected group compared to the nonejected group (P = .001). The overall mortality was 8.3%. On multivariate regression analysis, predictors of not using a seat belt were being a front seat passenger, driver, or Qatari national and young age. Unrestrained males had a 3-fold increase in mortality in comparison to unrestrained females. The risk of severe injury (relative risk [RR] = 1.82, 95% confidence interval [CI], 1.49-2.26, P = .001) and death (RR = 4.13, 95% CI, 2.31-7.38, P = .001) was significantly greater among unrestrained passengers.

CONCLUSION

The nonuse of seat belts is associated with worse outcomes during MVCs in Qatar. Our study highlights the lower rate of seat belt compliance in young car occupants that results in more severe injuries, longer hospital stays, and higher mortality rates. Therefore, we recommend more effective seat belt awareness and education campaigns, the enforcement of current seat belt laws, their extension to all vehicle occupants, and the adoption of proven interventions that will assure sustained behavioral changes toward improvements in seat belt use in Qatar.

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.

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.

Connecticut nighttime safety belt use

PROBLEM

Safety belt use in the United States, as measured over daylight hours, has risen steadily over recent years reaching 80% in 2004. Yet, using the National Highway Traffic Safety Administration's (NHTSA) Fatality Analysis Reporting System (FARS), safety belt use among fatally injured front seat outboard occupants of passenger vehicles was only between 42% and 46% for the years 1999 to 2003. One possible contributing factor is that safety belt use at night, when crash rates are highest, is lower than during the day.

METHOD

A full statewide nighttime belt use observation survey was conducted in 2004. This survey was conducted simultaneously with Connecticut's annual full statewide daytime belt use survey. Night belt use observations of drivers and passengers are possible using newly available near military grade night vision goggles and handheld infrared spotlights. Both day and goggle-assisted night observations were conducted at 100 observation sites in Connecticut. Procedures for day and night observations were as nearly identical as possible.

RESULTS

The night belt use rate was 6.4 percentage points lower than the day rate (83.0 vs. 76.6). Consistent with belt use among Connecticut fatalities, day versus night differences were greatest in urban areas. There was evidence that day versus night differences were greater before as compared to after a May 2004 belt use enforcement program.

Evaluation of the Reading, PA nighttime safety belt enforcement campaign: September 2004

PROBLEM

Safety belt use rates among front seat occupants of passenger vehicles are substantially lower at night than during the day despite the fact that night driving is more dangerous.

METHOD

Recent advances in night vision equipment now make it possible to enforce belt use laws in darkness. Reading, Pennsylvania conducted a night belt use publicity and enforcement campaign during September 2004 using night vision equipment.

RESULTS

Front seat occupant belt use at night increased significantly from 50% prior to the campaign to 56% just after the campaign. Daylight belt use also increased though to a lesser extent (56% to 59%). Survey data indicated that motorists had heard about the campaign in newspapers and on television. Belt use increases were not seen during the same time period in a comparison community.

Association of main driver-dependent risk factors with the risk of causing a vehicle collision in Spain, 1990-1999

PURPOSE

To assess the strength of association of main driver-dependent risk factors with the risk of causing a collision between vehicles in Spain, from 1990 to 1999.

METHODS

The data for this paired-by-collision, case-control study were obtained from the Spanish Dirección General de Tráfico traffic crash database. The study included all 220284 collisions involving two or more vehicles with four or more wheels, in which only one of the drivers involved committed an infraction. Infractor drivers comprised the case group; noninfractor drivers involved in the same collision were their corresponding paired controls.

RESULTS

All driver-dependent factors were associated with the risk of causing a collision. The highest adjusted odds ratio estimates were obtained for sleepiness (64.35; CI, 45.12-91.79), inappropriate speed (28.33; CI, 26.37-30.44), and driving under the influence of alcohol with a positive breath test (22.32; CI, 19.64-25.37). An increase in the number of years in possession of a driving license showed a protective effect, albeit the strength of the effect decreased as age increased.

CONCLUSIONS

Our results emphasize the urgent need to implement strategies aimed mainly at controlling speeding, sleepiness, and alcohol consumption before driving-the main driver-dependent risk factors for causing a vehicle collision.

Some methodological deficiencies in studies on traffic accident predictors

The paper discusses some methodological problems in (psychological) research on traffic accident predictors and reviews a convenience sample of the literature. Three methodological aspects are identified as being important: reliability of accident predictors, time period for accidents used as dependent variable, and culpability for accidents. Papers are scrutinized and most are found to be wanting in these aspects. Traffic researchers do not adhere to, or hardly even discuss, these basic methodological problems. It is concluded that the current research into (psychological) accident predictors is fraught with methodological deficiencies. Why most studies seem to be deficient in these aspects is not clear, as several researchers have pointed out these problems.

Personal, temporal and spatial characteristics of seriously injured crash-involved seat belt non-users in Hawaii

The characteristics of crash-involved seat belt non-users in a high use state (Hawaii) are examined in order to better design enforcement and education programs. Using police crash report data over a 10-year period (1986-1995), we compare belted and unbelted drivers and front seat occupants, who were seriously injured in crashes, in terms of personal (age, gender, alcohol involvement, etc.) and crash characteristics (time, location, roadway factors, etc.). A logistic regression model combined with the spline method is used to analyze and categorize the salient differences between users and non-users. We find that unbelted occupants are more likely to be male, younger, unlicensed, intoxicated and driving pickup trucks versus other vehicles. Moreover, non-users are more likely than users to be involved in speed-related crashes in rural areas during the nighttime. Passengers are 70 times more likely to be unbelted if the driver is also unbelted than passengers of vehicles with belted drivers. While our general findings are similar to other seat belt studies, the contribution of this paper is in terms of a deeper understanding of the relative importance of various factors associated with non-use among seriously injured occupants as well as demonstrating a powerful methodology for analyzing safety problems entailing the categorization of various groups. While the former has implication for seat belt enforcement and education programs, the latter is relevant to a host of other research questions.

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

There is a large difference between the rates of observed seat belt use by the general public and belt use by motor vehicle occupants who are fatally injured in crashes. Seat belt use rates of fatally injured occupants, as reported in the Fatality Analysis Reporting System (FARS), are much lower than the use rates found in observation surveys conducted by the states. A series of mathematical models describing the empirical relationship between FARS and observed rates were explored. The initial model was a 'straw man' and used two simplifying assumptions: (a) belt users and nonusers are equally likely to be involved in 'potentially fatal collisions', and (b) belts are 45% effective in preventing deaths. The model was examined by comparing each state's FARS use rate with the predicted rate. The model did not fit the state data points even when possible biases in the data were controlled. We next examined the assumptions in the model. Changing the seat belt effectiveness parameter provided a reasonable fit, but required an assumption that seat belts are 67% effective in preventing fatalities. The inclusion of a risk coefficient for non-belted occupants also provided a reasonable fit between the model and data. A variable risk model produced the best fit with the data. The major finding was that a model consistent with the data can be obtained by incorporating the assumption that nonusers of seat belts have a higher risk of involvement in potentially fatal collisions than do seat belt users. It was concluded that unbelted occupants are over-represented in fatal collisions for two reasons: (a) because of a greater chance of involvement in potentially fatal collisions in the first place, and (b) because they are not afforded the protection of seat belts when a collision does occur.

Human factors in the causation of road traffic crashes

Road traffic crashes (RTCs) are responsible for a substantial fraction of morbidity and mortality and are responsible for more years of life lost than most of human diseases. In this review, we have tried to delineate behavioral factors that collectively represent the principal cause of three out of five RTCs and contribute to the causation of most of the remaining. Although sharp distinctions are not always possible, a classification of behavioral factors is both necessary and feasible. Thus, behavioral factors can be distinguished as (i) those that reduce capability on a long-term basis (inexperience, aging, disease and disability, alcoholism, drug abuse), (ii) those that reduce capability on a short-term basis (drowsiness, fatigue, acute alcohol intoxication, short term drug effects, binge eating, acute psychological stress, temporary distraction), (iii) those that promote risk taking behavior with long-term impact (overestimation of capabilities, macho attitude, habitual speeding, habitual disregard of traffic regulations, indecent driving behavior, non-use of seat belt or helmet, inappropriate sitting while driving, accident proneness) and (iv) those that promote risk taking behavior with short-term impact (moderate ethanol intake, psychotropic drugs, motor vehicle crime, suicidal behavior, compulsive acts). The classification aims to assist in the conceptualization of the problem that may also contribute to behavior modification-based efforts.

A technology to measure multiple driving behaviors without self-report or participant reactivity

An in-vehicle information system (IVIS) was used to videotape drivers (N = 61) without their knowledge while driving 22 miles in normal traffic. The drivers were told that they were participating in a study of direction following and map reading. Two data-coding procedures were used to analyze videotapes. Safety-related behaviors were counted during consecutive 15-s intervals of a driving trial, and the occurrence of certain safety-related behaviors was assessed under critical conditions. These two methods of data coding were assessed for practicality, reliability, and sensitivity. Interobserver agreement for the five different driving behaviors ranged from 85% to 95%. Within-subject variability in safe driving was more pronounced among younger drivers and decreased as a function of age. Contrary to previous research that has relied on self-reports, driver risk taking did not vary significantly as a function of gender. These results are used to illustrate the capabilities of the technology introduced here to design and evaluate behavior-analytic interventions to increase safe driving.

Modelling the factors related to the seatbelt use by the young drivers of Athens

Road traffic accidents in Greece are one of the major problems of the public health sector and the first cause of death in the ages 18-24. However, there are no records available for defining the determinants of road accidents and seatbelt wearing rates. The main objective of this study is to determine and clarify the relationship between young drivers' intentions (motivation to use/non use seatbelt) and their behaviour (self-reported use). Additionally, the purpose of this study is to evaluate the seatbelt wearing rates among young drivers in relation to their trip-type. The sample consisted of 200 young Greek drivers of both sexes. The statistical analysis included factor analysis and multiple regression analysis. The seatbelt use was measured in relation with seven trip-types. Through factor analysis, a seven factor scale of seatbelt use and a four factor scale of seatbelt non use were created which included Greek young drivers' basic motivations for wearing or not wearing a seatbelt. A model, constructed by the multiple regression analysis, revealed the factors related with the seatbelt use. The factors positively related were 'imitation', 'self-protection', and 'legality'. The factor of 'discomfort' is negatively associated with the seatbelt use. Furthermore, mileage was negatively related with seatbelt use. Finally, some preliminary suggestions on how prevention strategies should be implemented in Greece are discussed.

Predictors of safety belt use among crash-involved drivers and front seat passengers: adjusting for over-reporting

Police-reported crash data are rarely used to investigate safety belt use and its predictors, even though these data have a number of advantages over data collected in roadside surveys. It has been widely recognized that motorists tend to over-report their safety belt use to police when mandatory belt use becomes law. In this paper, we use a logistic regression model that allows for misclassification errors in outcome variable to examine predictors of safety belt use among crash-involved drivers and front seat passengers. Our analysis shows significant associations between occupant characteristics, driving circumstances, and safety belt use. Alcohol involvement has the strongest negative association with safety belt use, but this association would be considerably underestimated without adjusting for the over-reporting of safety belt use in police-reported crash data. The adjusted belt use rate among front seat occupants with at least nonincapacitating injuries is about 81%, compared to 90% in police-reported crash data.

Factors associated with seat belt use: an evaluation from the Ontario Health Survey

This study examines the factors associated with seat belt use for drivers and passengers in Ontario. Using the 1990 Ontario Health Survey, a population-based survey of non-institutionalized Ontario residents, factors associated with seat belt use among drivers and passengers were identified and are reported as unadjusted and adjusted odds ratios (OR; 95% CI). Seat belt non-use in Ontario drivers was most strongly associated with younger age (p < 0.0001), high risk health behaviours (drinking and driving (OR: 2.43), speeding (OR: 2.04), smoking (OR: 1.66)), being male (OR: 1.87), living in northern (OR: 1.80) or rural (OR: 1.69) regions, and achieving lower education (OR: 1.46). Seat belt non-use in passengers was associated with younger age (p < 0.0001), smoking (OR: 1.62), being male (OR: 1.68), living in northern (OR: 1.63) or rural (OR: 1.46) regions, and low education (OR: 1.31). Vehicular trauma is a major public health problem and seat belt use has been shown to reduce injuries in the event of a crash. Any strategy to increase seat belt use in Ontario should be targeted to involve both drivers and passengers. Attention should be paid to increasing seat belt usage by younger adults, males, and especially those living in northern and rural regions.

Highway crash costs in the United States by driver age, blood alcohol level, victim age, and restraint use

This paper estimates 1993 U.S. highway crash incidence and costs by driver age, alcohol use, victim age, occupant status, and restraint use. Notable findings are: (1) crash costs of novice drivers are high enough to yield preliminary benefit-cost ratios around 4-8 for a provisional licensing system that restricts driving after midnight and 11 for zero alcohol tolerance for young drivers with violators receiving a 6-month suspension; (2) the costs to people other than the intoxicated driver per mile driven at BACs of 0.08-0.099% exceed the value of driver mobility; (3) the safety costs of drunk driving appear to exceed $5.80 per mile, compared with $2.50 per mile driven at BACs of 0.08-0.099%, and $0.11 per mile driven sober; (4) highway crashes cause an estimated 3.2% of U.S. medical spending, including more than 14% of medical spending for ages 15-24; (5) ignoring crash-involved occupants whose restraint use is unknown, the 13% of occupants who police reported were traveling unrestrained accounted for an estimated 42% of the crash costs; and (6) if these unrestrained occupants buckled up, the medical costs of crashes would decline by an estimated 18% (almost $4 billion annually) and the comprehensive costs by 24%.

Methodological issues in testing the hypothesis of risk compensation

The hypothesis of risk compensation implies that persons experiencing a real or perceived change in the riskiness of an activity will alter their consumption of that activity to obtain a preferred combination of risk and reward. In evaluating whether individuals display compensating behavior in response to safety interventions, not all persons subject to the intervention will necessarily display compensating behavior, even if the hypothesis is correct: the hypothesis has testable implications only for the subset of persons subject to the intervention who perceive that their risk has changed. This paper argues that methodologies that include persons for whom the hypothesis has no testable implications (against a null hypothesis of no compensation effect) result in estimates of the compensation effect and test statistics which are biased towards zero. Previously published data on motor-vehicle-related injuries to cyclists and pedestrians in Britain before and after a mandatory safety-belt-use law went into effect were used to infer the size of this bias. In these data, the inclusion of persons for whom the hypothesis of risk compensation has no testable implications appears to have resulted in estimates of a risk-compensation effect which are too small by about half. This work suggests that the British data are consistent with a risk-compensation effect of 7-13 percent, and raises important methodological issues in testing the hypothesis of risk compensation.

Prospective countywide evaluation of the effects of motor vehicle safety device use on hospital resource use and injury severity

STUDY OBJECTIVE

We evaluated the efficacy of safety devices (seat belts and air bags) on hospital resource use and injury severity while controlling for variables known to affect outcome of motor vehicle crashes.

METHODS

We conducted a prospective observational study of motor vehicle crash victims who were transported to the hospital in a suburban-rural county with a population of 1.4 million. Out-of-hospital providers recorded patient demographic characteristics, mechanism of injury (based on American College of Surgeons criteria), and use of seat belts or air bags. Hospital charts were reviewed for hospital admission, length of hospital stay, ICU stay, surgery, major nonorthopedic surgery or death, and severe injury (Injury Severity Score > 15).

RESULTS

The study group comprised 1,446 motor vehicle crash victims. Median age was 30 years, 47% were male, and 69% used safety devices. The use of safety devices reduced the likelihood of hospital admission (adjusted odds ratio [OR], .67; 95% confidence interval [CI], .46 to .98) surgery (adjusted OR, .52; 95% CI, .27 to 1.01), major surgery or death (adjusted OR, .14; 95% CI, .04 to .52), and severe injuries (adjusted OR of injury Severity Score > 15, .39; 95% CI, .19 to .83).

CONCLUSION

The use of safety devices is associated with decreased hospital resource use and less severe injuries for victims of motor vehicle crashes who are transported to the hospital by emergency medical services providers, even after adjustment for many other variables known to affect the outcome of motor vehicle crashes. Continued efforts to promote safety device use are warranted.

Seat belt use and accident involvement: a comparison of driving behavior before and after a seat belt law

In an earlier study, researchers at the University of North Carolina Highway Safety Research Center found drivers classified as seat belt nonusers on the basis of direct observation and self-reported belt use to be overrepresented in prior accidents and violations. This study represents a follow-up and extension of the earlier study where accident and violation rates over a 2.5-year interval following the classification by seat belt use status are compared. Seat belt nonusers were again found to be overrepresented in both accidents and violations. In other analyses of these data, changes in seat belt use status were found not to be associated with changes in accident or violation rates, and seat belt use rates reported by police in accidents following the mandatory seat belt law greatly exceeded both the observed and self-reported use rates. This was especially pronounced for drivers who responded that they rarely or never used seat belts.