Impact of safety belt use on road accident injury and injury type in Kuwait

The enactment of Kuwait's seat belt law in January 1994 provided an opportunity to examine the impact of seat belt use on road accident fatalities and injury types in this affluent Persian Gulf nation. Via a structured data form, the results of injurious/fatal road accidents for more than 1200 accident victims were gathered from the files of the six major government hospitals which treat most traffic accident victims. Statistical analysis of the data showed that seat belt use has had a positive effect in reducing both road traffic fatalities and multiple injuries in Kuwait. The use of seat belts has also affected the nature of the injuries resulting from road traffic accidents. Non-users of belts experienced higher frequencies of head, face, abdominal and limb injuries. Users of belts, on the other hand, suffered higher frequencies of neck and chest injuries. The interrelationship between the victim, his age, and the type of injuries resulting from road traffic accidents is also investigated.     

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.     

Using naturalistic driving data to identify variables associated with infrequent,occasional, and consistent seat belt use

Seat belt use is one of the most effective countermeasures to reduce traffic fatalities and injuries. The success of efforts to increase use is measured by road side observations and self-report questionnaires. These methods have shortcomings, with the former requiring a binary point estimate and the latter being subjective. The 100-car naturalistic driving study presented a unique opportunity to study seat belt use in that seat belt status was known for every trip each driver made during a 12-month period. Drivers were grouped into infrequent, occasional, or consistent seat belt users based on the frequency of belt use. Analyses were then completed to assess if these groups differed on several measures including personality, demographics, self-reported driving style variables as well as measures from the 100-car study instrumentation suite (average trip speed, trips per day). In addition, detailed analyses of the occasional belt user group were completed to identify factors that were predictive of occasional belt users wearing their belts. The analyses indicated that consistent seat belt users took fewer trips per day, and that increased average trip speed was associated with increased belt use among occasional belt users. The results of this project may help focus messaging efforts to convert occasional and inconsistent seat belt users to consistent users.     

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.     

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.     

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.     

A retrospective analysis of chest injuries in 280 seat belt wearers

The usefulness of seat belts is today well documented. The purpose of the present study was to analyse the factors which caused the fatal outcome of 207 seat belt wearers, a chest injury being recorded as the main cause of death. The control material consisted of 73 seat belt wearers who sustained severe chest injury in the same kind of traffic accidents. The basic material consisted of 3,468 traffic accidents investigated by the Boards of Traffic Accidents Investigation of Insurance Companies in Finland. Since 1972, the Boards have investigated accidents involving one or more victims dying within 30 days of the accident. In the group of fatally injured victims drivers outnumbered passengers statistically (p less than 0.01), this being the case especially in frontal impact collisions. In those frontal crashes the part of the car causing injury was the steering wheel in 28.6% of the cases, but in lateral collisions the injury was in 4.8% due to impact by steering wheel (p less than 0.001). In lateral impact collisions there were more fatalities compared with other directions of impact (p less than 0.001) and only 3.3% survived in the front seat on the side impact. The injury mechanism on the body was grouped as follows: deceleration, contusion, and crushing force. Crushing force was the most common mechanism leading to the fatal outcome and was statistically more common in lateral impact collisions than in other types of crashes (p less than 0.001). Improving the constructions of steering assembly and strengthening side panels of the cars can be considered one of the main priorities in the prevention of fatal chest injuries.     

Motorized two-point safety belt effectiveness in preventing fatalities

The effectiveness of two-point motorized restraint systems in preventing fatalities to outboard front-seat car occupants is estimated using published fatality data for one model car equipped with a motorized two-point-belt system, together with a number of assumptions. Effectiveness estimates are obtained for the motorized belt system as used in the field, which reflects the mix of occupants who do and do not fasten the manual lap belt, and for effectiveness when the lap belt is not used. This latter estimate is, therefore, an estimate of the effectiveness of shoulder belts in preventing fatalities. In the data for the one car model, 18% of the fatally injured occupants were ejected. By assuming that three-point belt systems prevent ejection, these data are used to compute the difference in effectiveness between two-point and three-point systems. The result applies to the two-point belt system used in conjunction with whatever manual belt-use rates occurred in traffic. From published observations of lap-belt-use rates for this same vehicle, the effectiveness of the shoulder belt only is estimated. It is found that effectiveness of the two-point restraint system in conjunction with the lap-belt use that occurred in traffic is (32 +/- 5)%. The effectiveness of the shoulder belt only is estimated as (29 +/- 8)%.     

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.     

Active transportation: Do current traffic safety policies protect non-motorists?

Objective

This study investigated the impact that state traffic safety regulations have on non-motorist fatality rates.

Methods

Data obtained from the National Highway Traffic Safety Administration (NHTSA), the Federal Highway Administration (FHWA), and the National Institute on Alcohol Abuse and Alcoholism (NIAAA) were analyzed through a pooled time series cross-sectional model using fixed effects regression for all 50 states from 1999 to 2009. Two dependent variables were used in separate models measuring annual state non-motorist fatalities per million population, and the natural log of state non-motorist fatalities. Independent variables measuring traffic policies included state expenditures for highway law enforcement and safety per capita; driver cell phone use regulations; graduated driver license regulations; driver blood alcohol concentration regulations; bike helmet regulations; and seat belt regulations. Other control variables included percent of all vehicle miles driven that are urban and mean per capita alcohol consumption per year.

Results

Non-motorist traffic safety was positively impacted by state highway law enforcement and safety expenditures per capita, with a decrease in non-motorist fatalities occurring with increased spending. Per capita consumption of alcohol also influenced non-motorist fatalities, with higher non-motorist fatalities occurring with higher per capita consumption of alcohol. Other traffic safety covariates did not appear to have a significant impact on non-motorist fatality rates in the models.

Conclusion

Our research suggests that increased expenditures on state highway and traffic safety and the initiation/expansion of programs targeted at curbing both driver and non-motorist intoxication are a starting point for the implementation of traffic safety policies that reduce risks for non-motorists.     

Restraint use legislation: Its prospects for increasing the protection of children in cars

Very few children traveling in cars—even fewer than adults—are restrained, and effective ways need to be found to increase their crash protection. One potential mechanism for accomplishing this goal is through laws requiring restraint use. Unfortunately, seat belt use laws have tended to exempt children, and the increases in restraint use and decreases in occupant fatalities that have resulted from some of these laws have not been shared by children. Empirical evidence from several countries indicates that children can be protected by seat belts, and thus they should be included in belt use legislation. Several Australian states have now extended restraint use legislation to children less than eight years old, requiring them to use seat belts or child restraints. In the United States, Tennessee has a law in force requiring use of child restraints by children less than four years old. Present child restraint laws have major gaps and shortcomings that limit their potential effectiveness, and the data available at this writing indicate that the effects of the laws have, at best, been slight. It is more likely that significant advances in protecting children in cars can be achieved through implementation of measures that provide protection automatically to virtually all the people for whom they are available, whether children or adults.     

Fatality risk for belted drivers versus car mass

This study was performed to determine how the likelihood of a belted driver being killed in a single car crash depends on the mass of the car. This was done by applying the pedestrian fatality exposure approach to the subset of fatalities in the Fatal Accident Reporting System (FARS) for which the driver was coded as using a shoulder belt and/or a lap belt. Combining the 1975 through 1982 data provided a sufficiently large population of belted drivers to perform the analysis. In the exposure approach used, the number of car drivers killed in single car crashes is divided by the number of nonoccupant fatalities (pedestrians or motorcyclists) associated with the same group of cars. The ratio is interpreted to reflect the physical effect of car mass, essentially independent of driver behavior effects. In the present application, car mass effects for belted drivers were determined by considering the number of belted drivers killed divided by the number of nonoccupants killed in crashes involving cars whose drivers were coded in the FARS files as being belted. Because the belt use of surviving drivers is, to some extent, self-reported, it is considered that the data given in the report should be not used to estimate the effectiveness of seat belts in preventing fatalities. The results are presented as graphical and analytical comparisons of fatality likelihood versus car mass for belted and unbelted drivers. It is concluded that the effect of car mass on relative driver fatality likelihood is essentially the same for belted and unbelted drivers (for example, the present analysis gives that a belted driver in a 900 kg car is 2.3 times as likely to be killed in a single car crash as is the belted driver in an 1800 kg car. The corresponding ratio determined here for unbelted drivers is 2.4). As a consequence of this conclusion, the relative effectiveness of seat belts in preventing driver fatalities is similar for cars of different masses.     

Determinants of road traffic safety: New evidence from Australia using state-space analysis

This paper examines the determinants of road traffic crash fatalities in Queensland for the period 1958–2007 using a state-space time-series model. In particular, we investigate the effects of policies that aimed to reduce drink-driving on traffic fatalities, as well as indicators of the economic environment that may affect exposure to traffic, and hence affect the number of accidents and fatalities. The results show that the introduction of a random breath testing program in 1988 was associated with a 11.3% reduction in traffic fatalities; its expansion in 1998 was associated with a 26.2% reduction in traffic fatalities; and the effect of the “Safe4life” program, which was introduced in 2004, was a 14.3% reduction in traffic fatalities. Reductions in economic activity are also associated with reductions in road fatalities: we estimate that a one percent increase in the unemployment rate is associated with a 0.2% reduction in traffic fatalities.     

An investigation of factors reducing seat belt use amongst Spanish drivers and passengers on urban roads

Seat belt use on Spain's highways is more than 80%, while on the urban roads this figure is around 50%. As there was little information available to explain the difference in seat belt use rates, the main aim of this study was to investigate why there is a lower rate of seat belt use on urban roads. A number of perceptions, beliefs and expectancies about seat belt use were examined to identify variables that discriminated between seat belt users and non-users on urban roads. The subjects were 398 undergraduate students (aged 17-47) studying at the University of Girona, Spain. On the urban roads reported discomfort from using the seat belt was higher, while perceptions of risk (for non-users), safety perceptions (for those using a seat belt), beliefs about the seriousness of a crash or the effectiveness of the seat belt were all lower than on the highway. Perceptions of safety, discomfort, and social influence predicted seat belt use on urban roads. Concern about being fined for not using a seat belt did not predict seat belt use. The results of this research suggest that in order to increase seat belt use on urban roads, the issue of discomfort must be addressed. In addition, prevention campaigns should include information about the effectiveness of the seat belt in preventing/reducing injuries or deaths on urban roads. The results also highlight the importance of social influence for determining seat belt use/non-use and the potential role social influence could play in increasing seat belt usage.     

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.     

Preliminary estimates of the effects of mandatory seat belt use laws

Analyses of motor vehicle fatality counts in New York and several comparison states for the years 1980 through 1985 indicate that New York's seat belt use law reduced fatalities by about nine percent during the first nine months of the law. This estimate is preliminary, and the estimated long-term effect of the law could change as more sophisticated analyses are applied to the data and as belt use changes (it had declined to less than 50 percent over most of the state by the end of the first year of the law). In addition, New York's law is one of the strongest in terms of enforceability, and the effect may be smaller in states with weaker laws. However, the estimated effect in New York is consistent with the experience of other countries with seat belt use laws.     

Risky driving related to driver and vehicle characteristics

This investigation was performed to determine relationships between driver and vehicle characteristics and risk taking in everyday driving, as measured by close following in freeway traffic. A total of 12,000 observations were made of headways (time intervals between successive vehicles) in high flow freely moving freeway traffic at two sites, one in Michigan, the other in Toronto, Canada. The headways were measured using a photographic technique which allowed vehicle and occupant characteristics to be recorded, including type of vehicle and sex and seat belt use. For the Michigan observations, the vehicle license number was recorded, from which additional information on the vehicle and owner (usually the driver) was obtained from state files, including the vehicle mass and model year and the owner's age. sex and history of recorded accidents and traffic violations. Shorter headways, corresponding to higher risk, were found for drivers with prior accidents or violations, young drivers, male drivers, drivers with no passengers. and drivers who did not wear a seat belt. Vehicles associated with shorter headways included newer cars and cars of intermediate mass (1600–1900 kg).     

The effectiveness of alcohol control policies on alcohol-related traffic fatalities in the United States

Multiple alcohol control policies have been enacted since the early 1980s to keep drunk drivers off the roads and to prevent more alcohol-related traffic fatalities. In this paper, we analyze nine traffic policies to determine the extent to which each policy contributes to effective alcohol-related fatality prevention. Compared with the existing literature, this paper addresses a more comprehensive set of traffic policies. In addition, we used a panel GLS model that holds regional effects and state-specific time effects constant to analyze their impact on alcohol-related fatalities with two distinct rates: alcohol-related traffic deaths per capita and alcohol-related traffic deaths per total traffic deaths. While per capita alcohol-related traffic deaths is used more often in other studies, alcohol-related traffic deaths per total traffic deaths better reflects the impact of policies on deterring drunk driving. In addition, regional analyses were conducted to determine the policies that are more effective in certain regions. The findings of this study suggest that zero tolerance laws and increased beer taxes are the most effective policies in reducing alcohol-related fatalities in all regions.     

A review of research on the protection afforded to occupants of cars by seat belts which provide upper torso restraint

The paper presents a critical review and summary of research on the protection afforded to car occupants by seat belts which provide upper torso restraint. The nature and causes of the injuries which occur even when seat belts are worn are then considered, and methods of reducing injuries still further are suggested.

Summaries are given of 8 selected European and American papers on seat belts in accidents. The estimated reductions in serious injuries varied from 45 to 70%, and reasons are suggested for the occurrence of these differences. Evidence of the reduction in deaths, as opposed to serious injuries, when seat belts are worn is scanty, but Australian experience of the results of compulsory seat belt wearing suggest that the wearing of seat belts with upper torso restraint reduces deaths of car occupants by at least 40%.

In non-fatal accidents to belted occupants, head, chest and leg injuries give rise to the largest numbers of severe injuries (AIS >3). In fatalities to belted occupants, however, while head injury retains its premier position, abdominal injury is at least as important as chest injury.

Modifications to the design of lap and diagonal seat belts are suggested, (a) to restrict loads on the abdomen and chest to levels which will not result in serious injury, and (b) to reduce forward movement of the head so as to lessen the risk of head injury.     

How would increasing seat belt use affect the number of killed or seriously injured light vehicle occupants?

The expected effects of increasing seat belt use on the number of killed or seriously injured (KSI) light vehicle occupants have been estimated for three scenarios of increased seat belt use in Norway, taking into account current seat belt use, the effects of seat belts and differences in crash risk between belted and unbelted drivers. The effects of seat belts on fatality and injury risk were investigated in a meta-analysis that is based on 24 studies from 2000 or later. The results indicate that seat belts reduce both fatal and non-fatal injuries by 60% among front seat occupants and by 44% among rear seat occupants. Both results are statistically significant. Seat belt use among rear seat occupants was additionally found to about halve fatality risk among belted front seat occupants in a meta-analysis that is based on six studies. Based on an analysis of seat belt wearing rates among crash involved and non-crash involved drivers in Norway it is estimated that unbelted drivers have 8.3 times the fatal crash risk and 5.2 times the serious injury crash risk of belted drivers. The large differences in crash risk are likely to be due to other risk factors that are common among unbelted drivers such as drunk driving and speeding. Without taking into account differences in crash risk between belted and unbelted drivers, the estimated effects of increasing seat belt use are likely to be biased. When differences in crash risk are taken into account, it is estimated that the annual numbers of KSI front seat occupants in light vehicles in Norway could be reduced by 11.3% if all vehicles had seat belt reminders (assumed seat belt wearing rate 98.9%), by 17.5% if all light vehicles had seat belt interlocks (assumed seat belt wearing rate 99.7%) and by 19.9% if all front seat occupants of light vehicles were belted. Currently 96.6% of all (non-crash involved) front seat occupants are belted. The effect on KSI per percentage increase of seat belt use increases with increasing initial levels of seat belt use. Had all rear seat occupants been belted, the number of KSI front seat occupants could additionally be reduced by about 0.6%. The reduction of the number of KSI rear seat occupants would be about the same in terms of numbers of prevented KSI.