Speed limits and fatality risk in Australia

Objectives: The objective of the current study was to quantify the effects of the strength of US state graduated driver licensing laws and specific licensing components on the rate of teenage driver fatal crash involvements per 100,000 teenagers during 1996–2007. The strengths of state laws were rated good, fair, marginal, or poor based on a system developed previously by the Insurance Institute for Highway Safety. Methods: Analysis was based on quarterly counts of drivers involved in fatal crashes. Associations of overall ratings and individual licensing components with teenage crash rates were evaluated using Poisson regression, with the corresponding fatal crash rate for drivers ages 30–59 controlling for state- or time-dependent influences on crash rates unrelated to graduated licensing laws. Results: Compared with licensing laws rated poor, laws rated good were associated with 30 percent lower fatal crash rates among 15- to 17-year-olds. Laws rated fair yielded fatal crash rates 11 percent lower. The longer the permit age was delayed, or the longer the licensing age was delayed, the lower the estimated fatal crash rates among 15- to 17-year-olds. Stronger nighttime restrictions were associated with larger reductions, and reductions were larger for laws limiting teenage passengers to zero or one than laws allowing two or more teenage passengers or laws without passenger restrictions. After the effects of any related delay in licensure were accounted for, an increase in the minimum learner's permit holding period showed no association with fatal crash rates. An increase in required practice driving hours did not appear to have an independent association with fatal crash rates. Conclusions: Graduated licensing laws that include strong nighttime and passenger restrictions and laws that delay the learner's permit age and licensing age are associated with lower teenage fatal crash rates. States that adopt such laws can expect to achieve substantial reductions in crash deaths.

BackgroundDespite substantial progress, motor vehicle crashes remain a leading killer of US children. Previously, we documented significant positive impacts of Safe Routes to School interventions on school-age pedestrian and pedalcyclist...

Objective: The objective of this study was to evaluate New Jersey's unique combination of a higher licensing age and a strong GDL system applicable to all novice drivers. Methods: Population-based crash rates for drivers of ages potentially affected by GDL were compared, pre- and post-GDL implementation, with those of adults ages 25–59, using data on fatal crashes and on all police-reported crashes. Results: After GDL implementation, there were statistically significant reductions in the crash rates of 17-year-olds, based on all reported crashes (16%), injury crashes (14%), and fatal crashes (25%), relative to those of drivers ages 25–59. The crash rates of 18-year-olds decreased significantly on the basis of all reported crashes (10%) and injury crashes (10%), relative to those of drivers ages 25–59. The fatal crash involvement rate of 18-year-olds decreased by 4 percent, which was not statistically significant. There was also a statistically significant reduction in fatal crashes of 16-year-old drivers; however, this is unlikely to have been attributable to GDL. Significant reductions in nighttime crashes (of all severity levels) of drivers ages 17 and 18 were observed, as were significant yet smaller reductions in their daytime crash rates. Reductions in fatal crashes of 17- and 18-year-olds carrying more than one passenger were sizable (23 and 24%, respectively) but were not statistically significant. Conclusions: New Jersey's licensing age of 17 eliminates most crashes at age 16. To the extent that the relative inexperience of 17-year-old drivers may negatively impact their crash rates, this effect appears to be largely blunted by New Jersey's strong GDL system. New Jersey's GDL system also reduces crashes at age 18, an age group untouched by other states' GDL systems. New Jersey's combination of licensing policies for young drivers is a model for the nation.

Debates regarding lowering the blood alcohol concentration (BAC) limit for drivers are intensifying in the United States and other countries, and the World Health Organization recommends that the limit for adults should be 0.05%. In January 2016, Uruguay implemented a law setting a zero BAC limit for all drivers. This study aimed to assess the effect of this policy on the frequency of moderate/severe injury and fatal traffic crashes. A quasi-experimental study in which a synthetic control model was used with controls consisting of local areas in Chile as the counterfactual for outcomes in Uruguay, matched across population counts and pre-intervention period outcomes. Sensitivity analyses were also conducted. Uruguay and Chile. Panel data with crash counts by outcome per locality-month (2013-2017). A zero blood alcohol concentration law implemented on 9 January 2016 in Uruguay, alongside a continued 0.03g/dl BAC threshold in Chile. Per-capita moderate/severe injury (i.e. moderate or severe), severe injury and fatal crashes (2013-2017). Our base synthetic control model results suggested a reduction in fatal crashes at 12months [20.9%; P-value=0.018, 95% confidence interval (CI)=-0.340, -0.061]. Moderate/severe injury crashes did not decrease significantly (10.2%, P=0.312, 95% CI=-0.282, 0.075). The estimated effect at 24months was smaller and with larger confidence intervals for fatal crashes (14%; P=0.048, 95% CI=-0.246, -0.026) and largely unchanged for moderate/severe injury crashes (-9.4%, P=0.302, 95% CI=-0.248, 0.058). Difference-in-differences analyses yielded similar results. As a sensitivity test, a synthetic control model relying on an inferior treatment-control match pre-intervention (measured by mean squared error) yielded similar-sized differences that were not statistically significant. Implementation of a law setting a zero blood alcohol concentration threshold for all drivers in Uruguay appears to have resulted in a reduction in fatal crashes during the following 12and 24months.

Fatal crashes in the 5 years after recreational marijuana legalization in Colorado and Washington

To analyze the characteristics of fatal ambulance crashes to assist emergency medical services (EMS) directors in objectively developing their EMS system's policy governing ambulance operations. No difference exists between the characteristics of fatal ambulance crashes during emergency and nonemergency use. Retrospective, cross-sectional, comparative analysis of ambulance crashes resulting in fatalities reported to the Fatal Accident Reporting System (FARS) from 1987 to 1990. Twenty variables, representing characteristics of fatal ambulance crashes, were selected from the National Highway Traffic Administration FARS Codebook and were evaluated using tests of significance for categorical data grouped by emergency use and nonemergency use. Crash variable categories examined included demographics, accident configuration, accident severity, vehicle description, and ambulance operator action. During the four-year study period, 109 fatal ambulance crashes occurred producing 126 deaths. Four states, New York, Michigan, California, and North Carolina, accounted for 37.5% of all fatal crashes. Seventy-five fatal crashes (69%) occurred during emergency use (EU) and 34 fatal crashes (31%) occurred during nonemergency use (NEU). The total number of fatal crashes varied in a downward trend (1987:32; 1988:24; 1989:28; 1990:25). The number of fatal EU crashes also varied in a downward trend (1987:28; 1988:16; 1989:19; 1990:12), while the number of fatal NEU crashes increased each year [1987:4; 1988:8; 1989:9; 1990:13](p = .016). Most EU fatal crashes occurred between 1200 h and 1800 h (p = .009). Most NEU fatal crashes occurred during times when light conditions were poor (p = .003). When a violation was charged to the ambulance driver (17 cited), the vehicle was more likely to be in EU (p = .056). No statistically significant differences between EU and NEU were identified by: 1) day of week; 2) season; 3) atmospheric conditions; 4) roadway surface type; 5) roadway surface condition; 6) speed limit; 7) roadway alignment; 8) relationship to junction; 9) manner of collision; 10) year manufactured; 11) vehicle role; 12) vehicle maneuver; 13) manner leaving scene; 14) extent of deformation; 15) violations charged; or 16) number of persons killed in accident. Few characteristics differentiate between fatal ambulance crashes during EU and NEU. The difference between EU and NEU were statistically significant in only three out of the 20 variables examined: 1) year occurred; 2) time of day; and 3) light condition. These data provide few objective measures that may be used to develop ambulance operation policies to decrease fatal ambulance crashes.

Pedestrian crashes are a major concern in the Northern Territory (NT), Australia, but the factors associated with these crashes differ from those in other Australian jurisdictions. This study aims to provide a comprehensive investigation of pedestrian crashes in the NT. Using police crash records and hospitalisation data, we conducted a retrospective observational analysis. We describe crash factors and calculate standardised rate ratios to compare involvement by gender, age and Aboriginal and Torres Strait Islander status. Stepwise logistic regression was used to explore crash factors contributing to fatal and 'severe injury collision' outcomes. Male pedestrians were 1.43 times (95% CI: 1.22-1.66) more likely to be involved in crashes and 1.38 times more likely to be hospitalised (95% CI: 1.23-1.56). Across all age groups, Aboriginal and Torres Strait Islander pedestrians had higher crash involvement and fatality rates. Among those aged 35-44 years, the likelihood of being involved in a fatal crash increased 35-fold (95% CI: 8.81-305.88), while severe injury risk increased 14-fold (95% CI: 8.83-23.81). Most crashes occurred during clear weather and light traffic, on straight, flat, sealed and dry roads. Factors that influence the severity of injuries in a pedestrian crash are visibility, road speed limit and driver and pedestrian alcohol and drug use. Improving lighting on roads with speed limits ≥ 70 km/h should be prioritised, or speed limits reduced where lighting upgrades are not feasible. Keeping people safe while they are intoxicated is a priority for reducing pedestrian injuries and deaths.

Alcohol-Related Motor Vehicle Crash Risk and the Location of Alcohol Purchase

Crash data in Kentucky show that the fatal crash rate on two-lane rural roads is substantially higher than on any other type of road. Improvements have been proposed at some locations on this type of road which involve either upgrading the existing two-lane road or adding lanes resulting in a four-lane road. As part of the public information process, highway officials have been asked to document the previous results of this type of construction. The objectives of this study were to: 1) identify sections of two-lane rural roadways where either the two-lane road had been realigned and reconstructed or additional lanes had been added and 2) conduct a before-and-after analysis to determine how these changes affected traffic crashes. Of the 49 locations included in the study, 25 involved adding lanes and converting to a four-lane road while the two-lane road was upgraded (realignment with wider lanes and shoulders) at 24 locations. Before the construction, the average traffic volume was almost three times higher on the roads where additional lanes were added than where the two-lane road was upgraded. The average daily traffic increased dramatically after the construction was completed with a slightly higher increase for roads where lanes were added. When all the locations are considered, there was a 51% reduction in the crash rate when the road was upgraded and a 56% reduction in the crash rate when lanes were added. The rate was reduced from 250 to 122 crashes/100 million vehicle miles (MVM) when the road was upgraded and from 258 to 114 crashes/100 MVM when lanes were added. When only the number of crashes is considered, the number of crashes per mile decreased by 39% when the road was upgraded and by 45% when lanes were added. The rate of injury or fatal crashes was reduced by 54% for upgrading the road and 55% by adding lanes, while the number of crashes per mile decreased by 43% both when the road was upgraded and when lanes were added. The overall conclusion of the study is that both upgrading two-lane rural roads and converting the road to four lanes are effective methods of reducing total crashes and injury or fatal crashes. The traffic volume would determine the appropriate alternative.

Problem: Electronic Stability Control (ESC) is believed to be among the most efficient vehicle safety interventions with reported effects around 50% for fatal single and rollover crashes. However, such estimates have used sample data, which have not controlled for the possibilities of self-selection, behavioral adaptation, increased access to the technology by less safe drivers, and the calculation of effects on very specific categories of crashes. Effects of ESC in the population can therefore be expected to be smaller than is currently believed. Method: National U.S. data for fatal crashes, driving exposure and other control factors, and market penetration of ESC over 1991–2021 were used to calculate whether the trends in fatalities over time in crash rates for singles, rollovers, and fatal crashes in general matched projections from estimates of effectiveness. Results: It was found that downward trends in the relevant crash types were generally present before ESC was introduced, and that the trends thereafter were weaker. Although some trends were consistent with effects of ESC, they were markedly smaller than the projected ones, and could be explained by other factors such as the number of vehicles per capita. At best, the effect for rollovers could be up to two-thirds of previous estimates, no effect was detected for singles, while for all fatal crashes results depended upon the type of analysis performed. These results conflict with conclusions in all published ESC crash sample studies, which have compared vehicles with and without ESC. This discrepancy can be explained by methodological errors in the previous studies using induced exposure methods and self-selected samples. Practical applications: Traffic safety may not be as much improved by technological interventions as believed. Alternative approaches to traffic safety are needed, which do not rely on technology that interferes with driver behavior.

Objective: State-level data have indicated that motor vehicle crash (MVC) fatality rates among the elderly vary widely across states. To date, the majority of states have implemented mature driver laws, which often require more frequent license renewals, in-person renewal, and vision testing for drivers above a certain age. We sought to evaluate the impact of mature driver laws on states’ MVC fatality rates among the elderly while examining other state-level determinants of MVC-related deaths.Methods: We performed a cross-sectional ecological study and modeled state MVC fatality rates for the population over age 65 as a function of state transportation policies and demographic, health system, population health, travel, and climate characteristics using a general linear model. Principal component analysis was used to reduce dimensionality of the data and overcome multicollinearity of state predictor variables.Results: Higher average temperature, higher gas prices, and a greater number of emergency medicine physicians to population size were significantly associated with lower MVC fatality rates. Positive predictors of MVC fatality rates were percentage of population overweight or obese and percentage with college degree over the age of 65. Having any restriction on elderly drivers was associated with a higher MVC fatality rate and no individual component of mature driver laws (shortened renewal cycle, in-person renewal, and vision testing) was significantly associated with lower fatality MVC rates for adults over 65.Conclusions: Mature driver laws are not associated with lower state MVC fatality rates among the elderly.

Road characteristics and environment factors associated with motorcycle fatal crashes in Malaysia

Incorporating systems thinking approach in a multilevel framework for human-centered crash analysis

BackgroundGraduated driver licensing (GDL) laws are associated with reduced crash rates per person-year among adolescents. It is unknown whether adolescents crash less per miles driven or drive less under GDL...

Incidence and characteristics of school bus crashes and injuries