Investigating driver injury severity patterns in rollover crashes using support vector machine models

Rollover crash is one of the major types of traffic crashes that induce fatal injuries. It is important to investigate the factors that affect rollover crashes and their influence on driver injury severity outcomes. This study employs support vector machine (SVM) models to investigate driver injury severity patterns in rollover crashes based on two-year crash data gathered in New Mexico. The impacts of various explanatory variables are examined in terms of crash and environmental information, vehicle features, and driver demographics and behavior characteristics. A classification and regression tree (CART) model is utilized to identify significant variables and SVM models with polynomial and Gaussian radius basis function (RBF) kernels are used for model performance evaluation. It is shown that the SVM models produce reasonable prediction performance and the polynomial kernel outperforms the Gaussian RBF kernel. Variable impact analysis reveals that factors including comfortable driving environment conditions, driver alcohol or drug involvement, seatbelt use, number of travel lanes, driver demographic features, maximum vehicle damages in crashes, crash time, and crash location are significantly associated with driver incapacitating injuries and fatalities. These findings provide insights for better understanding rollover crash causes and the impacts of various explanatory factors on driver injury severity patterns.     

切丝机维护模式刀辊低速自动旋转功能监控系统设计

切丝机是烟草制丝线主要设备。本文介绍运用艾默生CT驱动器的STO(Safe Torque Off)禁止力矩输出技术实现刀辊维护模式下的安全低速驱动。     

Modernization of the Driver Behaviour Questionnaire

IntroductionThe current study builds on previous versions of the Driver Behaviour Questionnaire (DBQ) by incorporating a larger sample of driving behaviors targeting inattention, distraction, aggressive driving, and health related to aging. The goals of this study were to determine if the resulting factor structure was consistent with a more contemporary view of unsafe driving behaviors, and to determine whether scores on the factors could predict self-reported collisions and police citations.MethodsThe instrument was given to a sample of 3295 drivers ranging in age from 19 to 80+ years old. It was divided in two sections, the first to provide demographic information and driving history data and the second containing 105 driver behavior questions.ResultsAn exploratory factor analysis resulted in a 65-item scale organized in four factors. The factors were labeled tentatively as Inattention Errors, Age-Related Problems, Distraction and Hurry, and Aggressive Violations. Regression analyses showed that the factors were predictors of self-reported, at-fault collisions and police citations.Practical implicationsThe factor scores found in this research are consistent with a useful theoretical framework for understanding unsafe driver actions, and demonstrate some potential to identify several individual difference variables that predict self-reported collisions and citations.     

Driving on the motorway: the effect of alternating speed on driver's activation level and mental effort

When most of the driving tasks are performed automatically, a driver's level of alertness may decline, as has been pointed out in the study of the phenomenon called ‘highway hypnosis’. One possible countermeasure is to periodically vary the speed (Wertheim 1978), but the authors have not found any studies that directly assess the effectiveness of this countermeasure. The objective of our study has been to provide empirical evidence regarding the effects of this strategy on the level of driver activation on a motorway route in real traffic. In the present study activation level as indexed by a relative measure based on slow EEG activity tended to be significantly higher when speed was modified periodically than when it remained constant. In addition, this index tended to be progressively higher when the speed was constant during the first part of the route, while the same thing did not occur when the speed was modified periodically. Finally, no significant differences between the constant and varying speed conditions were obtained with respect to any of the cardiovascular indices related to the effort put into driving and the stress experienced in the situation.     

The Relationship between Energy Expenditure and Pulse Rates with Body Weight and the Load Carried During Load Carrying on the Level

In a study of load carriage on the head on the level, high degrees of correlation worn obtained with the gross weights transported (viz. body weight and given load) and the energy expenditures, r = 0-91. Their relationship fits the equation, E(kcal/ minute) = 0.0943 (body weight+load carried) —2.183. The gross weight transported was also found to have an equally high correlation with the peak heart rates observed (r = 0.88) and the regression equation, PHR= 1.2552 (body weight-f load carried+-24.87, mathematically describes the relationship of the two latter variables. These equations can conveniently be utilized for field studies of load carrying in many underdeveloped countries where the common mode of load carriage is identical with that investigated hero and the average body weight of the subjects similar to that of the manual workers in this country, viz., around.50 kg     

The development of a multidimensional scale to evaluate motor vehicle dynamic qualities

Advances in motor vehicle engineering will allow greater refinement of the dynamic qualities of passenger cars in the near future. This paper describes the development and initial validation of a reliable and valid multidimensional scale to assess these parameters based upon a technique previously developed to evaluate aircraft handling qualities. The scaling methodology developed emphasizes the interaction between the vehicle's dynamic behaviour and the category of vehicle (e.g. sports car, executive saloon). This three-part study describes the initial extraction and the subsequent verification of the scale dimensions from an analysis of the opinions of circa 500 drivers, followed by an evaluation of the sensitivity and diagnosticity of the scale to distinguish between the road behaviour exhibited by vehicle types. The results suggest that the scale shows both content and construct validity, being able to distinguish both between broad categories of vehicle and different models of vehicle within a particular category in a consistent and meaningful manner.     

Safe mobility for elderly drivers—Considerations based on expert and self-assessment

To further understand the needs of the growing population of elderly drivers and create solutions for safe mobility it is important to understand the driving scenarios and aspects in day to day traffic that may be of challenge for this group. More so, individual differences in how drivers perceive their own driving ability may have an effect on how individuals limit their mobility and/or increase their exposure to risk situations, with a potential negative effect on safety.     

Real-time driver drowsiness feedback improves driver alertness and self-reported driving performance

Driver drowsiness has been implicated as a major causal factor in road accidents. Tools that allow remote monitoring and management of driver fatigue are used in the mining and road transport industries. Increasing drivers’ own awareness of their drowsiness levels using such tools may also reduce risk of accidents. The study examined the effects of real-time blink-velocity-derived drowsiness feedback on driver performance and levels of alertness in a military setting. A sample of 15 Army Reserve personnel (1 female) aged 21–59 (M = 41.3, SD = 11.1) volunteered to being monitored by an infra-red oculography-based Optalert Alertness Monitoring System (OAMS) while they performed their regular driving tasks, including on-duty tasks and commuting to and from duty, for a continuous period of 4–8 weeks. For approximately half that period, blink-velocity-derived Johns Drowsiness Scale (JDS) scores were fed back to the driver in a counterbalanced repeated-measures design, resulting in a total of 419 driving periods under “feedback” and 385 periods under “no-feedback” condition. Overall, the provision of real-time feedback resulted in reduced drowsiness (lower JDS scores) and improved alertness and driving performance ratings. The effect was small and varied across the 24-h circadian cycle but it remained robust after controlling for time of day and driving task duration. Both the number of JDS peaks counted for each trip and their duration declined in the presence of drowsiness feedback, indicating a dynamic pattern that is consistent with a genuine, entropy-reducing feedback mechanism (as distinct from random re-alerting) behind the observed effect. Its mechanisms and practical utility have yet to be fully explored. Direct examination of the alternative, random re-alerting explanation of this feedback effect is an important step for future research.     

On-road experiment to assess drivers’ detection of roadside targets as a function of headlight system,target placement,and target reflectance

Adaptive headlights swivel with steering input to keep the beams on the roadway as drivers negotiate curves. To assess the effects of this feature on driver’s visual performance, a field experiment was conducted at night on a rural, unlit, and unlined two-lane road during which 20 adult participant drivers searched a set of 60 targets. High- (n = 30) and low- (n = 30) reflectance targets were evenly distributed on straight road sections and on the inside or outside of curves. Participants completed three target detection trials: once with adaptive high-intensity discharge (HID) headlights, once with fixed HID headlights, and once with fixed halogen headlights. Results indicated the adaptive HID headlights helped drivers detect targets that were most difficult to see (low reflectance) at the points in curves found by other researchers to be most crucial for successful navigation (inside apex). For targets placed on straight stretches of road or on the outside of curves, the adaptive feature provided no significant improvement in target detection. However, the pattern of results indicate that HID lamps whether fixed or adaptive improved target detection somewhat, suggesting that part of the real world crash reduction measured for this adaptive system (Highway Loss Data Institute (HLDI), 2012a) may be due to the differences in the light source (HID vs. halogen). Depending on the scenario, the estimated benefits to driver response time associated with the tested adaptive (swiveling HID) headlights ranged from 200 to 380 ms compared with the fixed headlight systems tested.     

An experimental study of factors associated with driver frustration and overtaking intentions

This study examined directly the impact of various factors associated with driving on ‘A-class’ roads in the United Kingdom (specifically length of platoon, proportion of heavy goods vehicles (HGVs), speed and opportunities for overtaking) on self-reported frustration and overtaking intentions. The impact of situational variables (being under time pressure, and time behind a slower moving platoon) were also examined, as was the association between frustration and self-reported overtaking intentions. 183 members of the public from the areas around Perth and Inverness, Scotland took part in the study. Participants viewed simulated ‘driver’s viewpoint’ clips representing all the combinations of the experimental variables (except time pressure, which was a between-groups variable, and time behind platoon, which was examined separately in four specific clips). After each clip, participants responded on a paper questionnaire as to the level of frustration they would feel for a given clip, and the likelihood that at some point during the clip they would have attempted an overtake manoeuvre. The findings show that the links between traffic variables such as speed and platoon length, and behaviourally-relevant variables such as frustration and overtaking intentions, are not simple. Although there are broad and predictable effects of speed and platoon length (lower speeds and longer platoons leading to greater frustration) these are mediated by other variables, and it is not always the case that more frustration leads to more intention to overtake. Analysis of driver attitudes identified three clusters (low, medium and high risk drivers) and suggests that higher risk drivers’ levels of frustration are more affected by situational changes than those of lower risk drivers.