Search

Objectives:This study updates a 2006 report that estimated the historical effects of vehicle design changes on driver fatality rates in the United States, separate from the effects of environmental and driver behavior changes during the same period. In addition to extending the period covered by 8 years, this study estimated the effect of design changes by model year and vehicle type. Methods:Driver death rates for consecutive model years of vehicle models without design changes were used to estimate the vehicle aging effect and the death rates that would have been expected if the entire fleet had remained unchanged from the 1985 calendar year. These calendar year estimates are taken to be the combined effect of road environment and motorist behavioral changes, with the difference between them and the actual calendar year driver fatality rates reflecting the effect of changes in vehicle design and distribution of vehicle types. The effects of vehicle design changes by model year were estimated for cars, SUVs, and pickups by computing driver death rates for model years 1984–2009 during each of their first 3 full calendar years of exposure and comparing with the expected rates if there had been no design changes. Results:As reported in the 2006 study, had there been no changes in the vehicle fleet, driver death risk would have declined during calendar years 1985–1993 and then slowly increased from 1993 to 2004. The updated results indicate that the gradual increase would have continued through 2006, after which driver fatality rates again would have declined through 2012. Overall, it is estimated that there were 7,700 fewer driver deaths in 2012 than there would have been had vehicle designs not changed. Cars were the first vehicle type whose design safety generally exceeded that of the 1984 model year (starting in model year 1996), followed by SUVs (1998 models) and pickups (2002 models). By the 2009 model year, car driver fatality risk had declined 51% from its high in 1994, pickup driver fatality risk had declined 61% from its high in 1988, and SUV risk had declined 79% from its high in 1988. The risk of driver death in 2009 model passenger vehicles was 8% lower than that in 2008 models and about half that in 1984 models. Conclusions:Changes in vehicles, whether from government regulations and consumer testing that led to advanced safety designs or from other factors such as consumer demand for different sizes and types of vehicles, have been key contributors to the decline in U.S. motor vehicle occupant crash death rates since the mid-1990s. Since the early 1990s, environmental and behavioral risk factors have not shown similar improvement, until the recession of 2007, even though there are many empirically proven countermeasures that have been inadequately applied. [ABSTRACT FROM PUBLISHER]

Abstract: Current federal rule-making requires restraints such as air bags or automatic seat belts in new cars starting with model year 1987 unless states with two-thirds of the United States population enact seat belt use laws meeting certain criteria. Belt use laws have been enacted by 26 states and the District of Columbia as of July 1, 1986. The first laws to go into effect increased use from < 20 per ¢ to 50-70 per ¢ in the first month; m most cases rates subsequently dropped to below 50 per ¢. Texas has been an exception to this trend because it has had much tougher enforcement of its seat belt law than other states. This pattern is similar to the experience of Canadian provinces that passed laws in the mid-1970s; enforcement/publicity programs in Canada have produced belt use rates that are currently > 60 per ¢. An enforcement program in Elmira, New York also increased use rates sharply. New York, which had the first and one of the strongest and most successful laws so far, had an estimated fatality reduction of 9 per ¢ during the first nine months of the law. It is likely that a 10 per ¢ reduction in fatalities is the maximum that can be expected from belt use laws without special enforcement efforts. Provision of automatic restraints in combination with belt use laws would greatly increase crash protection. [ABSTRACT FROM AUTHOR]

Presents a study which compared injuries to front seat occupants in tow-away crashes in Charlottesville, Virginia for one year before and one year after the implementation of the seat belt use law in the state. Methods; Results; Conclusions.

The relationship of driver licensure rate differences to 16 year old lifestyles was assessed by surveying 15 and 16 year olds in New York, Michigan, and New Jersey. Michigan 16 year olds reported the highest rates of licensure (56 per cent), whereas New York (14 per cent licensed) and New Jersey (2 per cent licensed) had much lower rates. Teenagers in Michigan reported greater decreases in use of bicycles and reliance on parents and relatives for transportation but, for the most part, the differences in 16 year old licensure and mobility were not reflected in lifestyle differences. [ABSTRACT FROM AUTHOR]

Abstract: More than 5,000 miles of limited-access highways in the eastern United States and Canada were traveled to observe seat belt use. Overall belt use was 58 percent in the United States and 79 percent in Canada. The data indicate that belt use in the United States follows a different pattern on interstate highways than on other streets and roads, with relatively high belt use rates (over 50 percent) appearing to be somewhat independent of belt use law provisions. (Am J Public Health 1990; 80:740-742.) [ABSTRACT FROM AUTHOR]

The NERC Program conducted identically designed exposure-response studies of the respiratory and cardiovascular responses of rodents exposed by inhalation for up to 6 months to diesel and gasoline exhausts (DE, GE), wood smoke (WS) and simulated downwind coal emissions (CE). Concentrations of the four combustion-derived mixtures ranged from near upper bound plausible to common occupational and environmental hotspot levels. An "exposure effect" statistic was created to compare the strengths of exposure-response relationships and adjustments were made to minimize false positives among the large number of comparisons. All four exposures caused statistically significant effects. No exposure caused overt illness, neutrophilic lung inflammation, increased circulating micronuclei or histopathology of major organs visible by light microscopy. DE and GE caused the greatest lung cytotoxicity. WS elicited the most responses in lung lavage fluid. All exposures reduced oxidant production by unstimulated alveolar macrophages, but only GE suppressed stimulated macrophages. Only DE retarded clearance of bacteria from the lung. DE before antigen challenge suppressed responses of allergic mice. CE tended to amplify allergic responses regardless of exposure order. GE and DE induced oxidant stress and pro-atherosclerotic responses in aorta; WS and CE had no such effects. No overall ranking of toxicity was plausible. The ranking of exposures by number of significant responses varied among the response models, with each of the four causing the most responses for at least one model. Each exposure could also be deemed most or least toxic depending on the exposure metric used for comparison. The database is available for additional analyses.

Trends in motor vehicle occupant deaths over 8 years were studied for 24 states that raised interstate speed limits and seven states that did not following the 1995 repeal of the US National Maximum Speed Limit. Fatalities on interstates increased 15% in the 24 states that raised speed limits. After accounting for changes in vehicle miles of travel, fatality rates were 17% higher following the speed limit increases. Similar increases were reported following the 1987 speed limit increases on rural interstates. Deaths on roads other than interstates were essentially unchanged.

Context: Virtually all new cars now are equipped with passenger air bags. Determining whether passenger air bags are saving lives is important, particularly because passenger air bags have caused some deaths among children and adults., Objective: To assess the effectiveness of passenger air bags in reducing the risk of death in frontal crashes for right front passengers., Design: Air bags are designed to protect occupants in frontal crashes. Using Fatality Analysis Reporting System data for calendar years 1992 through 1995, the relative frequency of right front passenger deaths in frontal vs nonfrontal fatal crashes was compared for cars with dual air bags and for cars with driver-only air bags., Main Outcome Measures: Odds of right front passengers dying in frontal compared with nonfrontal fatal crashes were computed for 1992 through 1995 model year cars with dual air bags and for cars with driver-only air bags. Percentage reductions in right front passenger deaths in dual air bag vehicles were estimated., Results: Right front passenger fatalities were 18% lower than expected in frontal crashes of cars with dual air bags and 11% lower in all crashes. An estimated 73 fewer than expected right front passengers died in 1992 through 1995 model cars with dual air bags during 1992 through 1995. The risk of frontal crash death for right front passengers in cars with dual air bags was reduced 14% among those reported to be using belts and 23% among belt nonusers. Children younger than 10 years in cars with dual air bags had a 34% increased risk of dying in frontal crashes., Conclusions: Passenger air bags were associated with substantial reductions in fatalities among right front passengers in frontal crashes. However, more children are being killed than are being saved by air bags. Immediate countermeasures to reduce the dangers of air bags to children and adults are suggested.

Fatal crash rates of passenger cars and vans were compared for the last model year before four-wheel antilock brakes were introduced and the first model year for which antilock brakes were standard equipment. Vehicles selected for analysis had no other significant design changes between the model years being compared, and the model years with and without antilocks were no more than two years apart. The overall fatal crash rates were similar for the two model years. However, the vehicles with antilocks were significantly more likely to be involved in crashes fatal to their own occupants, particularly single-vehicle crashes. Conversely, antilock vehicles were less likely to be involved in crashes fatal to occupants of other vehicles or nonoccupants (pedestrians, bicyclists). Overall, antilock brakes appear to have had little effect on fatal crash involvement. Further study is needed to better understand why fatality risk has increased for occupants of antilock vehicles.

Objective: Analyses were conducted to estimate the effectiveness of airbags in reducing driver fatalities in motor vehicle crashes., Design: Airbag effectiveness was estimated by (1) comparing driver fatalities in frontal crashes with driver fatalities in nonfrontal crashes for cars with airbags and manual belts and cars with manual belts only, and (2) by comparing driver fatal crash rates per 10,000 registered vehicles for cars with airbags and manual belts and cars with manual belts only., Materials and Methods: Fatal Accident Reporting System data for 1985-1993 model year cars were compared., Measurements and Main Results: The two methods yielded similar results. In the analysis based on location of damage, driver fatalities in airbag equipped cars were reduced by 24 percent in frontal crashes relative to comparable cars with manual belts only and by 16 percent in all crashes. In the analyses based on vehicle registration data, fatality rates for frontal crashes were reduced by 23 percent for cars with airbags and manual belts compared with the same cars equipped with manual belts only and by 16 percent for all crashes., Conclusions: Various estimates of airbag effectiveness are beginning to yield consistent results. These analyses confirm that driver airbags are reducing fatalities in the frontal crashes for which they are designed.

Fatal crashes were tabulated for 6-hour periods around sunrise and sunset, from 13 weeks before the fall change to standard time until 9 weeks after the spring change to daylight saving time. Fatal-crash occurrence was related to changes in daylight, whether these changes occurred abruptly with the fall and spring time changes or gradually with the changing seasons of the year. During daylight saving time, which shifts an hour of daylight to the busier evening traffic hours, there were fewer fatal crashes. An estimated 901 fewer fatal crashes (727 involving pedestrians, 174 involving vehicle occupants) might have occurred if daylight saving time had been retained year-round from 1987 through 1991.

Psychologists are inadequately represented in the injury control field, despite the size of the problem and the importance of behavioral factors in injury. Using motor vehicle injuries as an example, this article discusses modern injury control principles and the role psychologists can play in injury reduction.

Studies of motor vehicle fatality data have indicated that alcohol involvement in fatal crashes has declined substantially in the United States since 1980. To determine the actual incidence of alcohol-impaired drivers on U.S. roads, a national roadside survey using portable breath-testing devices was carried out in 32 localities in the spring of 1986. The same sampling design and survey procedures used in a 1973 national roadside survey were followed as much as possible. The 1986 survey found 3.1% of the late-night weekend drivers to have a blood alcohol concentration (BAC) of 0.10% or more, compared to 4.9% of drivers in 1973. Similarly, 8.3% of the 1986 drivers were at or above 0.05% BAC, compared to 13.5% in 1973. The data indicate that the incidence of alcohol-impaired driving on weekend nights has fallen by one-third or more in the United States since 1973 and that the decline affected most population subgroups.

Usage of the automatic belt systems supplied by six large-volume automobile manufacturers to meet the federal requirements for automatic restraints were observed in suburban Washington, D.C., Chicago, Los Angeles, and Philadelphia. The different belt systems studied were: Ford and Toyota (motorized, nondetachable automatic shoulder belt), Nissan (motorized, detachable shoulder belt), VW and Chrysler (nonmotorized, detachable shoulder belt), and GM (nonmotorized detachable lap and shoulder belt). Use of automatic belts was significantly greater than manual belt use in otherwise comparable late-model cars for all manufacturers except Chrysler; in Chrysler cars, automatic belt use was significantly lower than manual belt use. The automatic shoulder belts provided by Ford, Nissan, Toyota, and VW increased use rates to about 90%. Because use rates were lower in Ford cars with manual belts, their increase was greater. GM cars had the smallest increase in use rates; however, lap belt use was highest in GM cars. The other manufacturers supply knee bolsters to supplement shoulder belt protection; all--except VW--also provide manual lap belts, which were used by about half of those who used the automatic shoulder belt. The results indicate that some manufacturers have been more successful than others in providing automatic belt systems that result in high use that, in turn, will mean fewer deaths and injuries in those cars.

A questionnaire survey of high school students conducted in 1983 provided information on their self-reported drinking and driving practices. By age 15 the majority reported drinking alcoholic beverages. By age 17 half or more of the males and one-third of the females reported driving after drinking at least once in the past month. About one-quarter of the students estimated that six or more cans of beer would be required to make someone an unsafe driver. Reported frequency of driving after drinking was associated with less time spent on homework and poorer academic performance, working part time, greater participation in social activities, less perceived parental influence regarding their travel, owning a car, driving high mileage, speeding, and having crashes and violations.

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.

Previous studies have shown that delaying licensure reduces motor vehicle injuries. This study examined the relationship between licensing laws and the timing of obtaining drivers licenses. The states studied have various laws, including minimum licensing ages of 15, 16 and 17; minimum learners permit ages of 15 and 16; and teenage night driving curfews. A questionnaire survey of 52,304 students was conducted in 75 high schools during the spring of 1983. The schools were selected from Orange County, California; rural Colorado; and most or all of Louisiana, Michigan, Mississippi, New Jersey and New York. The results indicated that the minimum age of licensure has obvious strong effects in delaying licensure. Setting the learners permit age later also apparently delays licensure. The night driving curfew in New York State (9 p.m.-5 a.m.) is seen by students as a factor in their decisions to delay obtaining licenses; Louisiana's 11 p.m.-5 a.m. curfew has a much smaller effect, if any.

As of April 1987, states were permitted to raise the speed limit on rural interstates to 65 mph without incurring federal sanctions; 38 states elected to do so in 1987. Fatality data for the months when the new limit was in effect in 1987 were compared with fatalities in the same months of 1982-86 on rural interstates and other rural roads. Fatalities on rural interstates in the states with increased speed limits in 1987 were conservatively estimated to be 15 percent higher than they would have been if the states had retained the 55 mph limit (95% CI = 6, 24). Among states that retained the 55 mph limit, fatalities on rural interstates were 6 percent lower than expected (95% CI = -23, 13).

The Health Belief Model is currently receiving substantial attention in the field of health education, not only because the Model attempts to explain health behavior but also because it specifies variables which are presumed to be modifiable. This article presents data from an adolescent population which contradict both of these assumptions. In addition, the data suggest that compliance with new preventive dental activities seems to be higher for children who have practiced similar activities before, with some minimal but not high level of parental involvement. However, in general, both health beliefs and acceptance of new activity were relatively unrelated to prior dental experiences and behavior among these children.

Although voluntary seat belt use rates are low, they are not uniform among different populations of U.S. drivers. In detailed analyses of 1982 data from 12 of the 19 cities in the National Highway Traffic Safety Administration's national seat belt survey and from three of the National Accident Sampling System regions, belt use rates varied greatly by geographic region, socioeconomic status and demographic group. These factors also moderated the effects of other factors such as car size and origin of manufacture. Nevertheless, all together, the factors included in the study explained less than 5% of the variation in voluntary seat belt use, and no subpopulation was identified in which seat belts were used by a majority of the members.

It is estimated that in 1985 about 1,560 fewer drivers were involved in fatal crashes because of three types of drinking-driving laws. The laws studied were per se laws that define driving under the influence using blood alcohol concentration (BAC) thresholds; laws that provide for administrative license suspension or revocation prior to conviction for driving under the influence (often referred to as "administrative per se" laws); and laws that mandate jail or community service for first convictions of driving under the influence. It is estimated that if all 48 of the contiguous states adopted laws similar to those studied here, and if these new laws had effects comparable to those reported here, another 2,600 fatal driver involvements could be prevented each year. During hours when typically at least half of all fatally injured drivers have a BAC over 0.10 percent, administrative suspension/revocation is estimated to reduce the involvement of drivers in fatal crashes by about 9 percent; during the same hours, first offense mandatory jail/community service laws are estimated to have reduced driver involvement by about 6 percent. The effect of per se laws was estimated to be a 6 percent reduction during hours when fatal crashes typically are less likely to involve alcohol. These results are based on analyses of drivers involved in fatal crashes in the 48 contiguous states of the United States during the years 1978 to 1985.

The Defensive Driving Course (DDC), like other post-licensure driver training programs, is intended to reduce the rate of motor vehicle crashes among those who take the course. A review of the literature revealed 14 controlled studies of the effects of DDC. About a third of these studies provided methodologically strong tests of DDC, but the remainder had design flaws that made their findings questionable or inadequate as tests of DDC. Only among the flawed tests were there large, positive effects of DDC. In the methodologically strong tests, DDC had no consistent effect on crashes but did decrease the frequency of traffic violations by about 10%. The failure of violation reductions to be translated into crash reductions may indicate that the violation reduction is an artifact of traffic record procedures or that the changes in driver behavior, if real, were insufficient to modify individual crash likelihoods. In either event, the best available evidence does not support the hypothesis that DDC decreases the likelihood of motor vehicle crashes.