The safety performance of connected vehicles on slippery horizontal curves through enhancing truck drivers’ situational awareness: A driving simulator experiment

Although drivers can adequately adjust their operating speed according to the road curvature, they show a lack of recognition regarding the pavement friction conditions. In this regard, inappropriate speed selection on Horizontal Curves (HCs) with reduced surface friction can lead to a remarkable rate of run-off-road, sideswipe, head-on, and rollover crashes, especially on rural highways. Aligned with the Connected Vehicle (CV) Pilot Program on Interstate-80 in Wyoming, this study scrutinizes how CV advisory/warning messages can enhance traffic safety on slippery HCs. To this aim, a roadway consists of two HCs with regular and slippery pavement conditions was designed in a high-fidelity driving simulator experiment. A total of 24 professional truck drivers were recruited to drive the simulated roadway under CV and non-CV environments. In the CV scenario, drivers were informed about the pavement conditions and the advisory speeds before entering HCs. In contrast, no messages were given to non-CV drivers. Truck drivers' behaviors in both scenarios were quantified using four Kinematic-based Surrogate Measures of Safety (K-SMoS), including deviation from the pathway, instantaneous acceleration, lateral speed, and steering angle. CVs’ trajectories were statistically compared to non-CVs in terms of the central tendency and dispersion using the Wilcoxon Signed-Rank Test (WSRT) and Median Absolute Deviation (MAD), respectively. The results of WSRT depicted, under the effect of CV advisory/warning messages and throughout the slippery HC, the central tendency of four K-SMoS could be shifted toward zero by 23% up to 99%. This shifting is associated with a significant safety enhancement that potentially can reduce the likelihood of curve-related crashes on slippery HCs. It was revealed that the variation in drivers’ behavior on the slippery HC could be minimized in the CV environment, where 54% up to 95% reduction in the dispersions of four K-SMoS were observed, leading to more certainty in drivers’ behavior.     

Factors affecting motorcyclists’ behavior in car-following condition

Car-following (CF) maneuver plays an important role in both traffic flow analysis and road safety assessment. However, many studies on this issue have focused on the drivers’ behaviour, neglecting the different driving behaviour of the motorcycle riders and the vulnerability of this type of user. The aim of the present paper is to analyse the factors affecting the riders’ behaviour in CF condition, by using two surrogate safety indicators, Time Headway (TH) and Time To Collision (TTC). A field experiment was conducted to collect data. Twenty young motorcyclists participated in the study driving their own motorcycles, which were instrumented with a camera and a global positioning system device (GPS). A digital image processing algorithm was used to obtain CF related indicators. The results of the study showed that Time Headway (TH) and Time To Collision (TTC) are independent of each other, extending the result obtained in the literature for the four wheeled vehicles to the motorcycles. TTC and TH were therefore analyzed separately. As for TTC, it was observed that only in few cases (0.8%) the riders were found in risky condition (TTC < 5 s), confirming the role of this parameter for the detection of an impending risk. On the other hand, TH gives information about a potentially risky situation, and 99% of the riders were found in such condition (TH < 2 s). Due to the few cases in TTC risky conditions, only TH was further modelled by using the hazard-based duration analysis. Accelerated Failure Time (AFT) model specification was used, and the Weibull distribution provided the best fit of the data. The model identified four covariates affecting TH and all of them had the effect of reducing TH, increasing the collision risk. The time spent on CF condition, the speed of the motorcycle, the willingness of overtaking and the engine size of the motorcycle were the factors that reduced TH.The findings of this study could be considered in the development of microsimulation models; the factors that were found affecting the motorcyclists’ behavior in car-following condition could be considered for a more realistic simulation of the riders’ choice of Time Headway.     

Influence of the median opening length on driving behaviors in the crossover work zone—A driving simulation study

Work zone safety has been a major concern for drivers and transportation agencies. Considering the severe consequences of crossover work zone crashes coupled with the limited literature on the median opening length, this paper aims to investigate the influence of the median opening length on driving behaviors from a behavioral perspective in crossover work zones. A driving simulation study with 32 participants was carried out to investigate the driving performance by metrics (speed, acceleration, maximum steering wheel speed, and lane-changing trajectory) with respect to five median opening lengths. The significant differences of each driving performance metric among various median opening lengths were found in the process of crossing through the median opening on the entrance by-pass and exit by-pass. The results indicated that drivers’ speeds were always higher than the speed limits for all median opening lengths. A narrower median opening may induce risky driving behaviors such as sharp deceleration and decelerating while lane-changing, which may increase speed variance. When crossing through the median opening with a larger length, high speed variance, sluggish lane-changing operations, and improper lane-using behaviors were observed because the excessive lane-changing space provided by the larger median opening length would decrease the situation awareness and increase the speed preference heterogeneity among drivers. Finally, some traffic management strategies were proposed, which can improve the safety and mobility of crossover work zones and further provide a basis for the formulation of related standards.     

The Mediation Effect of Ethical Leadership and Creative Performance: A Social Information Processing Perspective

Drawing upon social information processing theory, the study examined how ethical leadership shapes creative performance. Specifically, we tested a theoretical model integrating the sequential roles of psychological safety and creative self‐efficacy. A two‐waved sample of 512 supervisor‐subordinate dyads from frontline employees of three service industries located in Ghana was administered. The results of the hierarchical linear modeling analysis revealed that there is a positive relationship between ethical leadership and creative performance and that psychological safety positively and significantly mediates the relationship between ethical leadership and creative performance. Similarly, creative self‐efficacy significantly and positively mediates the relationship between ethical leadership and creative performance. Moreover, both psychological safety and creative self‐efficacy sequentially mediate the relationship between ethical leadership and creative performance. We discuss the implications of these results for research and practice.     

How to nudge drivers to reduce speed: The case of the left-digit effect

To decrease the negative consequences of a road crash, even a small reduction in driving speeds can make a significant difference. We examined the possible application of the left-digit effect as a nudge to reduce road speed. In the marketing field, this effect is based on reporting price tags that are characterized by a low leftmost number and a high rightmost number (e.g., a price tag of €14.99 rather than €15.00). We applied the same strategy to improve road safety. Participants were college students (43.75% female, mean age = 24.06 years in Study 1; 50% female, mean age = 23.53 years in Study 2) who were asked to drive in a simulator on a route that had both usual unmodified road signs (e.g., 50 km/h) and the same road signs increased or decreased by one unit (e.g., 49, 51 km/h). We compared the average median speeds in road segments with unmodified road signs with those in road segments with the corresponding modified signs. The average median speeds in the presence of a sign modified by the reduction of 1 km/h were significantly lower compared with the median average speeds recorded with unmodified signs. We showed that the application of psychological insights can reduce driving speeds and therefore increase road safety.     

Cognitive Behavior Therapy for Women With Generalized Anxiety Disorder in the Perinatal Period: Impact on Problematic Behaviors

Generalized anxiety disorder (GAD) is the most frequently diagnosed anxiety disorder among women in the perinatal period (pregnancy to one year postpartum). Recent studies have examined the relationship between problematic behaviors and GAD symptoms. Studies in nonperinatal samples indicate that adults with GAD engage in avoidance and safety behaviors and these behaviors are associated with greater symptom severity. Little research has examined the use of problematic behaviors among pregnant or postpartum women. However, preliminary research suggests that these behaviors may have a negative impact on both anxious women and their children. Our aim was to examine the extent to which women with GAD in pregnancy or the postpartum engage in problematic behaviors and whether cognitive behavioral therapy is effective in reducing these behaviors. Fifty-eight women with GAD in pregnancy or postpartum were recruited from a larger clinical trial (Clinicaltrials.gov ID NCT02850523) evaluating the effectiveness of group-based cognitive behavioral therapy (CBGT) for perinatal anxiety disorders. The results indicated that women with perinatal GAD reported high levels of avoidance and safety behaviors and greater engagement in these behaviors was associated with higher levels of worry and related symptoms. CBGT was effective in reducing GAD symptoms and problematic behaviors and a bidirectional relationship was found between changes in worry and problematic behaviors during treatment. Limitations and future directions are discussed.     

Breaking script: Deviations and postevent information in adult memory for a repeated event

Witnesses to industrial incidents may be asked to recall a single instance of a familiar event. This research systematically tested if deviations to what typically occurs and postevent information (PEI) enhanced reporting of an instance of a repeated event. Across 2 experiments, each participant experienced 5 food‐tasting instances; these instances comprised the repeated event. Half of the participants in both Experiments 1 (continuous deviation setting) and 2 (continuous deviation integrated) experienced a deviation to how the third instance occurred. Also, half of the participants in both experiments received PEI about the third instance. All participants demonstrated superior reporting for the first instance of the repeated event. The continuous deviation setting in Experiment 1 enhanced reporting for all 5 instances of the repeated event (general effect). In Experiment 2, participants who received a continuous deviation integrated and PEI demonstrated superior reporting for the first and third instances of the event (targeted effect).     

A novel conceptual framework investigating the relationship between roadside advertising and road safety: The driver behaviour and roadside advertising conceptual framework

This paper proposes a conceptual framework to understand the relationship between roadside advertising signs, driver behaviour, and road safety outcomes. Roadside advertising signs are external distractions that may take a driver's attention away from safety-critical driving tasks, potentially increasing crash risk through driver distraction and inattention. Although studies report safety concerns, as a whole, the body of research in the field is inconclusive with inconsistent quality, making it difficult to draw firm conclusions. Definitive links between roadside advertising and road trauma are not yet evident, which has major consequences for road regulators' capacity to develop evidence-based policy to safely administer public roads. However, a lack of consistent evidence does not indicate an absence of risk but underscores its complexity. To address this problem, the Driver Behaviour and Roadside Advertising Conceptual Framework (DBRA framework) was developed to strategically investigate and conceptualise the phenomena of roadside advertising. A new term – “extended engagement” – has also been proposed to account for situations of prolonged attentional engagement with a roadside advertising sign. Further, it is posited that important variations in driving performance may be associated with a driver's extended engagement with a roadside advertising sign. Built on extant theories of driver behaviour and empirical research, the DBRA framework is designed to be a robust tool that encourages a common agenda for future roadside advertising research.     

The impact of rail-based stations on passengers’ safety perceptions. A systematic review of international evidence

Feeling safe in public transport is essential for mobility, and fear of crime can be a larger problem for the individual than crime itself. The aim of the present paper is to systematically review the international evidence in rail-bound environments regarding (a) characteristics impacting safety perceptions and (b) behavioural consequences of unsafety, using the databases ScienceDirect, Scopus, PsycInfo, and Google Scholar. From a selection of 3226 publications, 52 were selected. The sample sizes range from 16 to 137 513 rail users or potential users. A social-ecological framework was adopted to categorize the findings in which place, social, individual, and temporal characteristics were identified along with short-term and long-term behavioural consequences of unsafety. Among the most important characteristics affecting passengers’ safety are lighting, surveillance, other persons’ behaviour, time of day, and one’s own gender. Future studies should further explore the complexity in interactions between characteristics connected to perceived safety.