Accident; analysis and prevention
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This research presents a modeling approach to investigate the association of the accident frequency during a snow storm event with road surface conditions, visibility and other influencing factors controlling for traffic exposure. The results have the premise to be applied for evaluating different maintenance strategies using safety as a performance measure. As part of this approach, this research introduces a road surface condition index as a surrogate measure of the commonly used friction measure to capture different road surface conditions. ⋯ It was found that the generalized NB model best fits the data, and is most capable of capturing heterogeneity other than excess zeros. Among the main results, it was found that the road surface condition index was statistically significant influencing the accident occurrence. This research is the first showing the empirical relationship between safety and road surface conditions at a disaggregate level (event-based), making it feasible to quantify the safety benefits of alternative maintenance goals and methods.
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Can commentary driving produce safer drivers? Producing a verbal commentary of potential hazards during driving has long been considered by the police to improve hazard perception skills. In this study we investigated whether learner drivers would benefit from being trained to produce a commentary drive. All learners were initially assessed on a virtual route in a driving simulator that contained 9 hazards. ⋯ The results showed that the trained group had fewer crashes, reduced their speed sooner on approach to hazards, and applied pressure to the brakes sooner than untrained drivers. Conversely the untrained drivers' behaviour on approach to hazards was symptomatic of being surprised at the appearance of the hazards. The benefit of training was found to be greater for certain types of hazard than others.
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To compare the differences in Canadian national estimates of correct child restraint use obtained using the standard roadside observation method compared to a detailed parking lot interview. ⋯ There are specific advantages and limitations to both survey designs. The purpose of the data collection must be considered when selecting the methodology. Parking lot surveys provide richer data regarding restraint use/misuse. Estimates of correct restraint use must be approached with caution due to the effect of consent bias resulting in over inflation of estimates. Roadside observation is adequate and appropriate for providing national estimates of correct restraint use.
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Pedestrian-injury severity has been traditionally modeled with approaches that have assumed that the effect of each variable is fixed across injury observations. This assumption ignores possible unobserved heterogeneity which is likely to be particularly important in pedestrian injuries because unobserved physical health, strength, and behavior may significantly affect the pedestrians' ability to absorb collision forces. ⋯ It was also found that the effect of pedestrian age was normally distributed across observations, and that as pedestrians became older the probability of fatal injury increased substantially. Heterogeneity in the mean of the random parameters for the freeway and pedestrian-solely-at-fault collision indicators was related to pedestrian gender, and heterogeneity in the mean of the random parameters for the traffic-sign and motorist-back-up indicators was related to pedestrian age.
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The severity of 1491 crashes on 148 roundabouts in Flanders-Belgium was examined in order to investigate which factors might explain the severity of crashes or injuries and to relate these factors to the existing knowledge about contributing factors for injury severity in traffic. Logistic regression and hierarchical binomial logistic regression techniques were used. A clear externality of risk appeared to be present in the sense that vulnerable road user groups (pedestrians, bicyclists, moped riders and motorcyclists) are more severely affected than others. ⋯ Single-vehicle crashes seem to have more severe outcomes than multiple-vehicle crashes. However, systematic differences in the reporting rate of crashes are likely to exist and may have affected the stated results. Correlations with important, but unobserved variables like the impact speeds in the crashes might exist as well and could provide an alternative explanation for some results.