An analysis of motorcycle injury and vehicle damage severity using ordered probit models

Problem: Motorcycles constitute about 19% of all motorized vehicles in Singapore and are generally overrepresented in traffic accidents, accounting for 40% of total fatalities. Method: In this paper, an ordered probit model is used to examine factors that affect the injury severity of motorcycle accidents and the severity of damage to the vehicle for those crashes. Nine years of motorcycle accident data were obtained for Singapore through police reports. These data included categorical assessments of the severity of accidents based on three levels. Damage severity to the vehicle was also assessed and categorized into four levels. Categorical data of this type are best analyzed using ordered probit models because they require no assumptions regarding the ordinality of the dependent variable, which in this case is the severity score. Various models are examined to determine what factors are related to increased injury and damage severity of motorcycle accidents. Results: Factors found to lead to increases in the probability of severe injuries include the motorcyclist having non-Singaporean nationality, increased engine capacity, headlight not turned on during daytime, collisions with pedestrians and stationary objects, driving during early morning hours, having a pillion passenger, and when the motorcyclist is determined to be at fault for the accident. Factors leading to increased probability of vehicle damage include some similar factors but also show some differences, such as less damage associated with pedestrian collisions and with female drivers. In addition, it was also found that both injury severity and vehicle damage severity levels are decreasing over time.     

Use and misuse of motor-vehicle crash death rates in assessing highway-safety performance

OBJECTIVES: The objectives of the article are to assess the extent to which comparisons of motor-vehicle crash death rates can be used to determine the effectiveness of highway-safety policies over time in a country or to compare policy effectiveness across countries. METHODS: Motor-vehicle crash death rates per mile traveled in the 50 U.S. states from 1980 to 2003 are used to show the influence on these rates of factors independent of highway-safety interventions. Multiple regression models relating state death rates to various measures related to urbanization and demographics are used. RESULTS: The analyses demonstrate strong relationships between state death rates and urbanization and demographics. Almost 60% of the variability among the state death rates can be explained by the independent variables in the multiple regression models. When the death rates for passenger vehicle occupants (i.e., excluding motorcycle, pedestrian, and other deaths) are used in the regression models, almost 70% of the variability in the rates can be explained by urbanization and demographics. CONCLUSIONS: The analyses presented in the article demonstrate that motor-vehicle crash death rates are strongly influenced by factors unrelated to highway-safety countermeasures. Overall death rates should not be used as a basis for judging the effectiveness (or ineffectiveness) of specific highway-safety countermeasures or to assess overall highway-safety policies, especially across jurisdictions. There can be no substitute for the use of carefully designed scientific evaluations of highway-safety interventions that use outcome measures directly related to the intervention; e.g., motorcyclist deaths should be used to assess the effectiveness of motorcycle helmet laws. While this may seem obvious, there are numerous examples in the literature of death rates from all crashes being used to assess the effectiveness of interventions aimed at specific subsets of crashes.     

Effect of novel divergence markings on conflict prevention regarding motorcycle-involved right turn accidents of mixed traffic flow

Introduction: In Taiwan, segregated traffic flow countermeasures have long been in place. Although these facilities have decreased the numbers of motorcycle left-turn collisions, right-angle collisions, and sideswipe collisions, they have also induced serious right-turn accidents. The purpose of this research was to evaluate an intervention intended to decrease conflicts and motorcycle-involved crashes. In this study, the reasons why the motorcycle accident rate is higher at intersections with slow lanes than at those without slow lanes are presented, and the theory of the self-explaining road was applied to create divergence markings for a mixed traffic flow environment. An intervention that guides motorcycles and cars into appropriate locations at intersections was applied to three intersection approaches. Method: The intervention effectiveness was evaluated by comparing the number of accidents at the intersections before and after the implementation of improvement measures. Moreover, video recordings were used to analyze the traffic distributions at the cross-sections of intersections. T-test was adopted to examine whether the traffic flows at the cross-sections of the intersections before and after the intervention were statistically different. In addition, this research applied the post-encroachment time (PET), the time between the first road user leaving the encroachment zone and the second road user arriving in it, to evaluate traffic conflicts. Finally, the PET and severity index between a straight-through motorcycle and a right-turn vehicle were analyzed. Results: PET increased by 3.2%–20.4%, and the rates of right-turn collisions, sideswipe collisions, and rear-end collisions decreased by 64.3%, 77.3%, and 61.5% respectively. Conclusions: Eliminating the slow traffic lane and setting divergence markings may not effectively cause vehicles in different driving directions to drive in the proper locations in the lanes. However, divergence markings both reduce the rate of right-turn collisions and decrease the incidence of sideswipe and rear-end collisions. Practical applications: The proposed design method may be a good design reference for countries having a high motorcycle density.     

Role of motorcycle type in fatal motorcycle crashes

IntroductionMotorcycles vary in design and performance capability, and motorcyclists may select certain motorcycle types based on driving preferences. Conversely, motorcycle performance capability may influence the likelihood of risky driving behaviors such as speeding. Both mechanisms may affect fatal crash risk when examined by motorcycle type. Although it was not possible to estimate the effect of each mechanism, the current study analyzed fatal crash data for evidence of motorcycle type differences in risky driving behaviors and risk of driver death.MethodsStreet legal motorcycles were classified into 10 types based on design characteristics and then further grouped as cruiser/standard, touring, sport touring, sport/unclad sport, supersport, and all others. For each motorcycle type, driver death rates per 10,000 registered vehicle years and the prevalence of fatal crash characteristics such as speeding were analyzed. Differences among motorcycle types concerning the effect of engine displacement were examined using Poisson regression.ResultsOverall, driver death rates for supersport motorcycles were four times as high as those for cruiser/standard motorcycles. Fatally injured supersport drivers were most likely to have been speeding and most likely to have worn helmets, but least likely to have been impaired by alcohol compared with drivers of other motorcycle types. The patterns in driver factors held after accounting for the effects of age and gender. Increased engine displacement was associated with higher driver death rates for each motorcycle type.ConclusionStrong effects of motorcycle type were observed on driver death rates and on the likelihood of risky driving behaviors such as speeding and alcohol impairment. Although the current study could not completely disentangle the effects of motorcycle type and rider characteristics such as age on driver death rates, the effects of both motorcycle type and rider age on the likelihood of risky driving behaviors were observed among fatally injured motorcycle drivers.Impact on IndustryCertain motorcycle designs, particularly supersport motorcycles, are associated with increases in risky driving behaviors and higher driver death rates. At present, there are no proven countermeasures for this situation. However, existing countermeasures such as helmet laws and automated speed enforcement could have a substantial benefit.     

Decomposition analysis of the effects of vehicle safety technologies on the motor vehicle collision–related mortality rate from 1994 to 2015

Abstract

Objective: Though the mortality rate for motor vehicle collisions (MVCs) has been decreasing since the 1960s with the advent of the first federal seat belt laws in 1968, MVC remains a leading cause of death for individuals aged 1 to 44 years. The purpose of this study is to examine the effects of frontal (FABs) and side airbags (SABs) and electronic stability control (ESC) on the components of the MVC mortality rate.

Methods: The MVC mortality rate from 1994 to 2015 was separated into its components of exposure of vehicles, exposure of travel, collision density, injury incidence, and case fatality rate. Year was categorized on the availability of safety technology in vehicles: 1994–1997 (first-generation FABs mandated), 1998–2001 (sled-certified, second-generation FABs mandated), 2002–2006 (increasing prevalence of SABs and ESC), 2007–2011 (advanced airbags mandated), and 2012–2015 (ESC mandated, SAB in over 90% of vehicles, introduction of advanced safety systems). Relative contributions (RCs) of the components to changes in the MVC-related mortality rate were calculated as the absolute value of the component’s beta coefficient divided by the sum of the absolute values of all components’ beta coefficients. Negative binomial regression–estimated rate ratios (RRs) for the changes in the rate of each component by year category compared to the prior year category.

Results: Significant decreases in the MVC mortality rate were observed for 2007–2011 and 2012–2015. The decrease in 2007–2011 was due in most part to an 18% decrease in the injury incidence (RR?=?0.82, P?<?.0001, RC?=?63%), though there was a noted contribution by the decrease in vehicle miles traveled (RR?=?0.95, P?<?.0001, RC?=?15%). The continued decrease in mortality in 2012–2015 was due is most part to the 10% decreased case fatality rate (RR?=?0.90, P?<?.0001, RC?=?66%) because there was no significant change in the vehicle miles traveled and injury incidence.

Conclusions: The results of this study highlight the effects of vehicle safety technologies on the MVC-related mortality rate and can help direct prevention efforts. Through the study period, there was no meaningful contribution to decreases in the MVC-related mortality rate due to components related to exposure (i.e., vehicles per population and the rate of vehicle miles traveled), suggesting that prevention efforts at decreasing exposure prevalence would have little effect on the MVC-related mortality rate. Instead, prevention efforts should continue to focus on event-phase methods to decrease injury occurrence and mitigate injury severity during the collision.     

The role of sales of new motorcycles in a recent increase in motorcycle mortality rates

INTRODUCTION: The National Highway Traffic Safety Administration (NHTSA) has reported that mortality rates from crashes among motorcycle riders in the United States increased from 21.0 per 100 million motorcycle miles traveled in 1997 to 38.4 per 100 million motorcycle miles traveled in 2003. At the same time, annual domestic sales of new, on-road motorcycles increased from 247,000 in 1997 to 648,000 in 2003. METHOD: This study used data from the NHTSA Fatality Analysis Reporting System and annual sales figures for on-road motorcycles to determine if newer motorcycles were more likely to be involved in fatal crashes and if fatal crashes involving newer motorcycles could account for the mortality increase after 1997. RESULTS: Mortality rates were 7.9, 8.1, 5.4, and 2.9 per 10,000 motorcycles sold for motorcycles <1, 1-3, 4-6, and 7-11 years old, respectively, from 1994 to 2003. Assuming complete registration, the number of motorcycles sold during the 2000-2003 time period accounted for 42.4% of the total number of motorcycles registered in 2003. Motorcycles sold during 2000-2003 were associated with 52.5% of all motorcycle deaths in 2003. The increase in the number of deaths associated with motorcycles less than four years old between 1997 and 2003 accounted for 78.1% of the total increase in motorcyclist deaths over this time period. CONCLUSIONS: Two possible explanations for the association between high sales volumes and mortality rates are: (a) increased exposure from more extensive use of motorcycles when they are new; and (b) inexperience with motorcycle riding or with specific motorcycles. IMPACT ON INDUSTRY: This study suggests that the deaths of growing numbers of motorcyclists are a consequence of the financial success of the motorcycle industry.     

Survival risk factors for fatal injured car and motorcycle drivers in single alcohol-related and alcohol-unrelated vehicle crashes

Introduction

A high percentage of drivers who die as a result of a single vehicle crash are under the influence of alcohol. We aimed to better understand the prevalence of these fatalities and the ratio of death to injuries based on various risk factors. We focused on alcohol-related and -unrelated single-vehicle crashes to investigate the influence of such risk factors on the time until death for car and motorcycle drivers.

Methods

We combined data from national police reports and a vital registration database in Taiwan. Survival analysis using Cox regression models was used to identify the risk factors of time until death.

Results

Overall, nearly 60% of car driver fatalities and 40% of motorcycle driver fatalities involved the consumption of alcohol. Survival analysis of single-vehicle crashes suggested that the traffic island separation between a car moving at a higher speed and motorcycle traffic resulted in a higher risk of death over time for motorcycle drivers who consumed alcohol. The factors attributed to a higher risk of death over time for motorcycle drivers were older age, crashing into trees, night-time driving, driving on curved roads, and driving on local roads. Driving without restraints and driving on roads with higher speed limits attributed to a higher risk of death over time for car drivers.

Conclusions

The factors that influence the risk of death over time in a motor-vehicle accident involving alcohol depended on different elements, which should each be considered when attempting to reduce this risk.

Impact on Industry

More efforts should be made to investigate the various risk factors in areas with large motorcycle populations.     

Why the per capita traffic fatality rate is falling

Various fatality rates are compared, and the historical relationship between the fatality rate per capita and the vehicle miles of travel is explored. There is an indication of travel saturation beginning about 1979.     

The sources of the Kuznets relationship between the road deaths to road injuries ratio and economic growth

Introduction: Past empirical studies indicated that there is a Kuznets or reverse U-shaped relationship between road deaths and per capita income, such that the number of road death increases at a low level of per capita reverse U-shaped relationship was observed between road injuries and per capita income. While these studies explored the impact of per capita income on road deaths and road injuries, no studies have examined the relationship between per capita income and road death to road injury ratio (DPI). Method: Using a fixed effects panel regression analysis from 67 countries spanning over a period of five decades (1960–2013), the present study sought to explore the impact of per capita gross domestic product (per capita GDP) on the DPI ratio and the underlying factors responsible for the relationship. Results: Our result suggests that per capita GDP followed a reverse U-shaped relationship with DPI. Moreover, the relative improvements in higher mobility roads as compared to improvements in higher accessibility roads, motorcycle ownership to passenger car ownership ratio, percentage of population living in an urban area, infant mortality rate, and the percentage of population below 15 years of age and above 64 years of age contributed to this relationship. Practical Applications: This implies that, at lower level of economic growth where road deaths exceed road injuries, countries should implement low-cost measures to combat road deaths cases. Such measures include mandating wearing of quality helmets and daytime running headlights for motorcycles. On the other hand, at higher level of economic growth where road injuries surpass road deaths, countries are encouraged to devote more resources to improving medical technology and services to treat road injury victims, mandating seatbelt use, as well as enhancing and promoting public transportation service.     

Motorcyclist injury severity in angle crashes at T-junctions: Identifying significant factors and analysing what made motorists fail to yield to motorcycles

Evidence in literature suggested that motorists’ failure to give way to motorcycles at junctions is the main contributory factor to motorcycle–car accidents that involve gap acceptance (i.e., approach-turn and angle crashes). This paper attempts to examine how motorist’s failure to give way affects motorcyclist injury severity in angle crashes at T-junctions, while controlling for other factors (demographic, vehicle, crash, and environmental factors). Binary logistic models of motorcyclist injury severity were estimated using the data extracted from the Stats19 accident injury database (1991–2004). Angle collisions were classified into several sub-crashes based on the manoeuvres motorcycles and cars were making prior to the accidents. The modelling results showed that injuries were greatest when a travelling-straight motorcycle on the main road crashed into a right-turn car from the minor road, particularly at stop-/yield-controlled junctions. Such crash pattern was assumed to be an accident involving right-of-way violation. Using binary logistic models, factors determining the likelihood of motorist’s failure to yield to motorcycles were also examined. The implications of the research findings of this present study were provided.     

Occupational road trauma and permanent medical impairment

Medically impairing occupational injuries sustained in traffic in Sweden were analysed. More than half of the cases with a permanent medical impairment were caused by minor injuries. Soft tissue injuries to the neck (whiplash injuries) made up nearly half of all permanently impairing injuries, and half of these were caused by rear-end collisions. As a final result, just over one third (37%) of the total group had a permanent decreased work capacity, or needed to change jobs because of residual problems from their injuries. Professional drivers had the highest injury incidence per employed and they accounted for 28% of the total number of permanent impairment cases, and for 43% of the fatalities. Professional drivers also had a higher percentage of serious injuries and severe permanent impairments than other occupational groups. This might be associated with the low use of safety belts (16%) compared to other occupational groups, where usage was 4–5 times higher. This occupational injury problem ought to be handled in the same way as other occupational safety problems, i.e. protective equipment in a vehicle should be used and the use of safe vehicles should be encouraged.     

A case study analysis to examine motorcycle crashes in Bogota,Colombia

IntroductionContributory factors to motorcycle crashes vary among populations depending on several aspects such as the users' profiles, the composition and density of traffic, and the infrastructure features. A better understanding of local motorcycle crashes can be reached in those places where a comprehensive analysis is performed. This paper presents the results obtained from a case study analysis of 400 police records of accidents involving motorcycles in Bogota.MethodTo achieve a deeper level of understanding of how these accidents occur, we propose a systemic approach that uses available crash data. The methodology is inspired by accident prototypical scenarios, a tool for analysis developed in France.ResultsWhen grouping cases we identified three categories: solo motorcycle accidents, motorcyclist and pedestrian accidents, and accidents involving a motorcycle and another vehicle. Within these categories we undertook in-depth analyses of 32 groups of accidents obtaining valuable information to better comprehend motorcyclists' road crashes in a local context. Recurrent contributory factors in the groups of accidents include: inexperienced motorcyclists, wide urban roads that incite speeding and risky overtaking maneuvers, flowing urban roads that encourage high speed and increased interaction between vehicles, and lack of infrastructure maintenance.Practical ApplicationsThe results obtained are a valuable asset to define measures that will be conveniently adapted to the group of accident on which we want to act. The methodology exposed in this paper is applicable to the study of road crashes that involve all types of actors, not only the motorcyclists, and in contexts different than those presented in Bogota.     

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.     

Motorcycle helmet effect on a per-crash basis in Thailand and the United States

OBJECTIVE: To compare the effectiveness of motorcycle helmets seen in prospective on-the-street motorcycle accident investigations. The data are drawn from two detailed, in-depth studies of motorcycle accidents, in which trained investigators collected extensive accident evidence on-scene immediately after the crash. This article compares helmeted and unhelmeted motorcycle riders on a per-accident basis for fatality rates, the rate of serious (AIS > 2) brain injuries among survivors, or an outcome that involved either of the two. METHODS: Nine hundred motorcycle crashes in Los Angeles and 969 crashes in Thailand were investigated in detail at the accident scenes, including photos of vehicles, skids, damage, and sometimes the rider. Helmets were collected and injury information was obtained from riders and care providers. This evidence was then used to reconstruct collision events to identify speeds, precrash motions, collision contacts, injury causation, and helmet performance. RESULTS: In both studies, approximately 6% of riders were killed and 20-25% were hospitalized. Overall, unhelmeted riders were two to three times as likely to be killed, and three times as likely to suffer either death or survival with AIS > 2 brain injury. Unhelmeted survivors had three to four times as many AIS > 2 brain injuries as helmeted riders on a per-crash basis. Nearly 100% of riders with AIS > 4 somatic injuries died. Such injuries were 30% of Thailand fatalities and 57% of L.A. fatalities, but only about 2-3% of the overall accident population. Among the 97-98% of riders with AIS < 5 somatic injuries, helmet use could prevent about three-fourths of fatalities and brain injuries. CONCLUSIONS: Helmets were extremely effective in preventing brain injury and death in 97% of the accident population in less-than-extreme crashes. Helmet use cannot prevent all fatalities because many of those killed succumb to below-the-neck injuries that a helmet cannot prevent.     

Florida's weakened motorcycle helmet law: effects on death rates in motorcycle crashes

OBJECTIVES: Effective July 1, 2000, Florida's universal helmet law was amended to exclude riders ages 21 and older with insurance coverage providing at least 10,000 US dollars in medical benefits for injuries sustained in a motorcycle crash. Observed helmet use in Florida was reported to have declined from nearly 100% in 1998, before the law change, to 53% after. This study examined the effects of the law change on the likelihood of death, given involvement in a motorcycle crash. METHODS: Rates of motorcyclist deaths per crash involvement in Florida for 2001-2002 (after the law change) were compared with those for 1998-1999 (before the law change). Before/after death rate ratios (95% CIs) were examined, and logistic regression models estimated the effect of the helmet law change on the odds of death in a crash, while controlling for rider gender, age, and seating position, and number of vehicles. RESULTS: The motorcyclist death rate increased significantly after the law change, from 30.8 to 38.8 deaths per 1,000 crash involvements. Motorcyclist death rates increased for single- and multiple-vehicle crashes, for male and female operators, and for riders of all ages including those younger than 21. After controlling for gender and age, the likelihood of death given involvement in a motorcycle crash was 25% higher than expected after the law change. It is estimated that 117 motorcyclist deaths could have been avoided during 2001-2002 if Florida's universal helmet law had remained in place. CONCLUSIONS: This study provides evidence of the life-saving benefits of universal helmet laws. The results also suggest that age-specific helmet laws are not effective in protecting the youngest drivers. This is not surprising, as these laws are largely unenforceable.     

Turning at intersections and pedestrian injuries

OBJECTIVE: To evaluate if precrash vehicle movement is associated with the severity of pedestrian injury. METHODS: We used comprehensive information on pedestrian, vehicle, and injury-related characteristics gathered in the Pedestrian Crash Data Study (PCDS), conducted by the National Highway Traffic Safety Administration (NHTSA) (1994-1998). The odds ratio of severe injuries (injury severity score >/= 15) and crash fatality rate for right- and left-turn collisions at intersection compared with straight vehicle movement were compared using a logistic regression model and taking into consideration the type of vehicle and age of the pedestrians as potential effect modifiers. Later we evaluated the intermediate effect of impact speed on the association by adding it to the logistic regression model. RESULTS: Of 255 collisions eligible for this analysis, the proportion of pedestrian hit during straight movement, right turns, and left turns were 48%, 32%, and 10%, respectively. Sixty percent of the pedestrians in left-turn crashes and 67% of them in right-turn collisions were hit from their left side. For straight movements the pedestrians were equally likely to be struck beginning from the left or right side of the street.After adjustment for pedestrian's age, vehicle movement was a significant predictor of severe injuries (p < 0.0001) and case fatality (p = 0.003). The association between vehicle precrash movement and severe injuries (p = 0.551) and case fatality (p = 0.912) vanished after adjusting for impact speed. This indicated that the observed association was probably the result of the difference in impact speed and not the precrash movement of the vehicle. CONCLUSION: Pedestrian safety interventions that aim at environmental modifications, such as crosswalk repositioning, might be the most efficient means in reducing right- or left-turn collisions at intersection, while pedestrians' behavioral modifications should be the priority for alleviating the magnitude of the collisions that happen in vehicles' straight movements.     

Mode choice model for vulnerable motorcyclists in Malaysia

OBJECTIVE: In developing countries, motorcycle use has grown in popularity in the past decades. Commensurate with this growth is the increase in death and casualties among motorcyclists in these countries. One of the strategic programs to minimize this problem is to reduce motorcyclists exposure by shifting them into safer modes of transport. This study aims to explore the differences in the characteristics of bus and motorcycle users. It identifies the factors contributing to their choice of transport mode and estimates the probability that motorcyclists might change their travel mode to a safer alternative; namely, bus travel. METHODS: In this article, a survey of 535 motorcycle and bus users was conducted in seven districts of Selangor state, Malaysia. A binary logit model was developed for the two alternative modes, bus and motorcycle. RESULTS: It was found that travel time, travel cost, gender, age, and income level are significant in influencing motorcyclists' mode choice behavior. The probability of motorcycle riders shifting to public transport was also examined based on a scenario of a reduction in bus travel time and travel cost. CONCLUSIONS: Reduction of total travel time for the bus mode emerges as the most important element in a program aimed at attracting motorcyclists towards public transport and away from the motorcycle mode.     

Side impact crashes--factors affecting incidence and severity: review of the literature

Many traffic crashes are side impact collisions resulting in significant death and injury. A review was conducted of the evidence of driver, road, and vehicle characteristics affecting either the risk of occurrence or the severity of injury in such crashes for papers published from 1996 to early 2003. For drivers, evidence was found of increased crash risk or injury severity only for age and age-related medical conditions (e.g., dementia). Traffic roundabouts and other traffic control devices--stop signs, traffic lights, and so on--had mixed results; traffic controls were better than no controls, but their effectiveness varied with circumstance. Most vehicle characteristics have had little or no effect on crash occurrence. Antilock braking systems (ABS) in the striking vehicle had been anticipated to reduce the risk of crashes, but so far have demonstrated little effect. The primary emphasis in vehicle design has been on protective devices to reduce the severity of injury. Disparity in the size of the two vehicles, especially when the struck vehicle is smaller and lighter, is almost a consistent risk factor for occupant injury. The occupants of light trucks, however, when struck by passengers cars on the opposite side, were at higher risk of injury. Wearing seat belts had a consistently protective effect; airbags did not, but there were few studies, and no field studies, of lateral airbags found. Of all the characteristics examined, vehicle design, including occupant restraints, is the most easily modified in the short term, although road design, traffic control, and the monitoring of older drivers may also prove effective in reducing side impact crashes in the longer term.     

Efficacy of side airbags in reducing driver deaths in driver-side car and SUV collisions

OBJECTIVE: To estimate the efficacy of side airbags in preventing driver deaths in passenger vehicles struck on the driver side. METHODS: Risk ratios for driver deaths per driver-side collision were computed for side airbag-equipped cars and SUVs, relative to vehicles without side airbags. Driver fatality ratios also were calculated for the same vehicles in front and rear impacts, and these were used to adjust the side crash risk ratios for differences in fatality risk unrelated to side airbags. Risk ratios were calculated separately for side airbags providing torso-only protection and side airbags with head protection; almost all head protecting airbags also had airbags protecting the torso. RESULTS: Car driver death risk in driver-side crashes was reduced by 37 percent for head protecting airbags and 26 percent for torso-only side airbags. Car driver death risk was reduced for older and younger drivers, males and females, and drivers of small and midsize cars, and when the striking vehicle was an SUV/pickup or a car/minivan. Death risk for drivers of SUVs was reduced by 52 percent with head protecting side airbags and by 30 percent with torso-only airbags. The effectiveness of side airbags could not be assessed for pickups and minivans due to the small number of these vehicles with airbags involved in crashes. CONCLUSION: Side airbags substantially reduce the risk of car and SUV driver death in driver-side collisions. Making side airbags with head protection available to drivers and right front passengers in all passenger vehicles could reduce the number of fatalities in motor vehicle crashes in the United States by about 2,000 each year.     

Characteristics of vehicle-animal crashes in which vehicle occupants are killed

During the past 10 years almost 1,500 people have been killed in motor vehicle collisions with animals. Police reports on 147 fatal vehicle-animal crashes during 2000-2002 were obtained from nine states. The goal was to determine common crash types, types of animals involved, and steps that could be taken to reduce the crashes and injuries. Seventy-seven percent of the struck animals were deer, but six other types of animals were involved including small ones such as dogs. Eighty percent of the crashes were single-vehicle events. In most of these cases a motorcycle struck an animal and the rider came off the vehicle, or a passenger vehicle struck an animal and then ran off the road; in a few cases the animal went through the windshield. Multiple-vehicle crashes included vehicles striking deer that went through the windshields of oncoming vehicles, vehicles striking animals and then colliding with other vehicles, and vehicles striking animals that subsequently were struck by other vehicles. Crashes occurred primarily in rural areas, on roads with 55 mph or higher speed limits, during evening or nighttime hours, and in darkness. Greater application of deer-vehicle collision countermeasures known to be effective is needed, but it is noteworthy that a majority of fatalities occurred from subsequent collisions with other vehicles or objects, not from animal contacts. Sixty-five percent of motorcyclists killed were not wearing helmets, and 60% of vehicle occupants killed were unbelted; many of these fatalities would not have occurred with proper protection.