Evaluating the influence of approaching vehicles on pedestrian’s visual patterns and crossing behaviors at an uncontrolled crosswalk

The visual behaviors and movement characteristics of pedestrians are related to their surrounding potential safety hazards, such as approaching vehicles. This study primarily aimed to investigate the visual patterns and walking behaviors of pedestrians interacting with approaching vehicles. Field experiments were conducted at two uncontrolled crosswalks located at the Cuihua and Yanta roads in Xi’an, China. The visual performance of pedestrians was assessed using the eye tracking system from SensoMotoric Instruments (SMI). Moreover, motion trajectories of the pedestrians and approaching vehicles were obtained using an unmanned aerial vehicle. Subsequently, the visual attributes and movement trajectories of pedestrians and motion trajectories of approaching vehicles were statistically analyzed. The results showed that approaching vehicles distracted the fixation of crossing pedestrians significantly, and occupied 29.5% of the total duration of fixation; that is, pedestrians always directed more fixation points to the approaching vehicles compared to other stimuli. As a vehicle approached, pedestrians’ fixation shifted from other areas of interest to the vehicle. Moreover, an increase in the velocity of the vehicle and a closer distance between pedestrian and the vehicle resulted in an increase in the pedestrians’ duration of fixation on the approaching vehicle, and they implemented more saccades. Furthermore, approaching vehicle’s velocity and distance between pedestrian and approaching vehicle are not significantly associated with pedestrian’s movement attributes. These findings provide insights into the crossing behavior of pedestrians during pedestrian-vehicle interactions, which could assist future researchers and policy makers.     

隆乳术的演变与进步

隆乳术不仅可以重塑女性的形体美,而且可以增强女性的自信心,在当前具有广阔的市场。纵观隆乳术的发展演变史,从最初的注射隆乳术到自体组织隆乳术,再到当前的假体隆乳术和自体脂肪移植隆乳术,经历了“实践、认识、再实践、再认识”的多次反复。各种隆乳方式各具特色,其间既有成功的经验,又有失败的教训。针对隆乳术安全性的改进推动了隆乳术的不断向前发展。寻找一种安全有效的隆乳方式和理想的隆乳材料成为当前隆乳术发展的关键和整形外科医师关注的重点。     

Crossing road intersections in old age—With or without risks? Perceptions of risk and crossing behaviours among the elderly

Pedestrians aged over 65 are known to be a critical group in terms of road safety because they represent the age group with the highest number of fatalities or injured persons in road accidents. It is widely recognized that the latter is due to the physical vulnerability of this age group in case of injury. However, physical and cognitive decline come into play during the action of crossing a street. Various studies have attempted to connect the crossing behaviours of the elderly with variables such as age, gender, sensory acuity, level of attentiveness, physical decline and the design of intersections. In demonstrating the complexity of the relationship between people and their environments, the literature suggests that age, physical ability, and the spatial configuration of roads are major components of road safety. Moreover, people’s knowledge and mastery of their environments, as well as their ability to adapt to change affects how they move through space. Taking these factors into account, this study examines the perceptions of elderly pedestrians with regards to the quality and risks of road crossings in the context of Montréal, Québec, in Canada. The analyze are based on observations and questionnaires in order to bring to light a better understanding of the relationship between the crossing behaviours, characteristics and perceptions of the elderly. While previous studies have examined perception and observation separately, this study is unique in having looked at both angles simultaneously. Five profiles of elderly people in both urban and suburban environments were established. A sample of 181 elderly pedestrians (65–93 years of age, AVG = 74) were surveyed using a questionnaire. In addition to close-ended questions, respondents were asked to evaluate 17 environmental ambiance and risk behaviours according to various scales. Using principal component analysis (PCA) and hierarchical cluster analysis (HCA), the data was grouped into 6 categories that define and distinguish 7 profiles of elderly people. These profiles were explored according to the socioeconomic status and crossing behaviours of respondents. The probabilities of adopting different crossing behaviours were tested by employing logistic regression models. The results reveal greater variability in the perceptions of the elderly in terms of risk related to crossing behaviours and type of signalisation at intersections. Even among seniors, the perceptions of risk varied greatly, which may have had an impact on their behaviours. While some of the behaviours observed coincided with the perceptions of respondents, the results of this study suggest that they only play a marginal role.     

Professional drivers’ fatigue as a problem of the modern era

ObjectiveAll around the world numerous studies have been carried out and indicated that 20–50% of commercial vehicle accidents occur because of fatigue. Professional drivers represent an important category of drivers who are present in traffic on a daily basis transporting passengers or goods and their responsibility is at a very high level. These drivers are most exposed to the impact of fatigue. The review of the literature has provided three main factors which can influence the onset of fatigue: sleep factors, work factors, health factors. The main aim of this study was to determine the influence of the three main factors of fatigue between bus and truck drivers in the Republic of Serbia.MethodsThe survey has been conducted among bus and truck drivers who are employed in transportation companies across the Republic of Serbia. The research consists of collecting and analyzing bus and truck drivers’ answers according to the above mentioned factors which influence the occurrence of fatigue.ResultsIn this study we have found that circadian rhythm, sleep and work factors have an impact on drivers’ fatigue. On the other side, time of going to sleep has no impact on the quality of sleep and on fatigue. The results show that if the drivers work over the legal limit, they are 3 times more likely to sleep less than 6 h in 24 h and if they sleep less than 6 h, it is likely that the poor quality of their sleep will be 8 times higher. The poor quality of sleep reduces driver performance, and therefore increases the risk of accidents.Conclusions2 of 3 investigated factors have an impact on the occurrence of fatigue. The third factor, health factor, should be examined in more detail, and other elements should be analysed in order to determine their influence on the fatigue.     

Investigating cycling kinematics and braking maneuvers in the real world: e-bikes make cyclists move faster,brake harder,and experience new conflicts

Pedelecs (e-bikes), which facilitate higher speeds with less effort in comparison to traditional bicycles (t-bikes), have grown considerably in popularity in recent years. Despite the large expansion of this new transportation mode, little is known about the behavior of e-cyclists, or whether cycling an e-bike increases crash risk and the likelihood of conflicts with other road users, compared to cycling on t-bikes. In order to support the design of safety measures and to maximize the benefits of e-bike use, it is critical to investigate the real-world behavior of riders as a result of switching from t-bikes to e-bikes.Naturalistic studies provide an unequaled method for investigating rider cycling behavior and bicycle kinematics in the real world in which the cyclist regularly experiences traffic conflicts and may need to perform avoidance maneuvers, such as hard braking, to avoid crashing. In this paper we investigate cycling kinematics and braking events from naturalistic data to determine the extent to which cyclist behavior changes as a result of transferring from t-bikes to e-bikes, and whether such change influences cycling safety.Data from the BikeSAFE and E-bikeSAFE naturalistic studies were used in this investigation to evaluate possible changes in the behavior of six cyclists riding t-bikes in the first study and e-bikes in the second one. Individual cyclists’ kinematics were compared between bicycle types. In addition, a total of 5092 braking events were automatically extracted after identification of dynamic triggers. The 286 harshest braking events (136 cases for t-bike and 150 for e-bike) were then validated and coded via video inspection.Results revealed that each of the cyclists rode faster on the e-bike than on the t-bike, increasing his/her average speed by 2.9–5.0 km/h. Riding an e-bike also increased the probability to unexpectedly have to brake hard (odds ratio = 1.72). In addition, the risk of confronting abrupt braking and sharp deceleration were higher when riding an e-bike than when riding a t-bike.Our findings provide evidence that cyclists’ behavior and the way cyclists interact with other road users change when cyclists switch from t-bikes to e-bikes. Because of the higher velocity, when on e-bikes, cyclists appear to have harder time predicting movements within the traffic environment and, as a result, they need to brake abruptly more often to avoid collisions, compared with cycling on t-bikes. This study provides new insights into the potential impact on safety that a cycling society moving to e-bikes may have, indicating that e-cycling requires more reactive maneuvers than does cycling traditional bicycles and suggesting that any distractive activity may be more critical when riding e-bikes compared to traditional bikes.     

Investigating the effectiveness of perceptual treatments on a crest vertical curve: A driving simulator study

Rural roads are characterized by a high percentage of run-off-the-road accidents and head-on collisions, mainly caused by inappropriate speeds and failure to maintain a proper lateral position along the roadway alignment. Among several road safety treatments, low-cost perceptual measures are considered an effective tool, as they generally increase the risk perceived by drivers, or even alter the drivers’ speed perception, and consequently tempting them to decrease their speeds. Their effectiveness has been widely recognized in a number of studies, especially with respect to road intersections and curves.The overall aim of this study is to investigate the effects of different perceptual treatments on driving speed, along a crest vertical curve of an existing two-lane rural road, in order to identify the most effective measure to reduce speed and define its subsequent implementation in the field. Three perceptual treatments were tested using a driving simulator: white peripheral transverse bars, red peripheral transverse bars and optical speed bars, with each one being painted along the approaching tangent to the crest vertical curve. The effects of these speed-reducing measures were investigated using a sample of forty-four participants, by comparing the driving speeds with those recorded under a baseline condition (without a treatment); these were also used to validate the driving simulator’s speed measurements with those found in the field. Moreover, subjective measures were collected, consisting of the driver’s static evaluation of the desired speed, risk perception and markings comprehension, based on screen shot pictures that represented the simulated configurations of the treatments.The findings demonstrated an overall effectiveness of the perceptual treatments, although only the red peripheral transverse bars were found to significantly reduce the driving speeds (−6 km/h). The analysis of the questionnaire yielded interesting information and demonstrated the importance of performing driving simulation tests for evaluating the effectiveness of perceptual treatments.Finally, the results confirmed the enormous potential of using driving simulators to pinpoint a number of speed-reducing measures, and consequently select the most effective one that reduces cost and promotes safety before its actual implementation in the field.     

Safety Behavior After Extinction Triggers a Return of Threat Expectancy

Safety behavior is involved in the maintenance of anxiety disorders, presumably because it prevents the violation of negative expectancies. Recent research showed that safety behavior is resistant to fear extinction. This fear conditioning study investigated whether safety behavior after fear extinction triggers a return of fear in healthy participants. Participants learned that two stimuli (A and C) were followed by an aversive loud noise (“threat”), and one stimulus (B) was not. Participants then learned to use safety behavior that prevented the loud noise. Next, A and C were no longer followed by the loud noise, which typically led to extinction of threat expectancy. Safety behavior then became available again for C, but not for A and B. All participants used safety behavior on these C trials. In a final test phase, A, B, and C were presented once without the availability to use safety behavior. At each stimulus presentation, participants rated threat expectancy by indicating to what extent they expected that the loud noise would follow. Compared with the last extinction trial, threat expectancy increased for C in the test phase, whereas it did not increase for A and B. Hence, safety behavior after the extinction of classically conditioned fear caused a partial return of fear. The findings suggest that safety behavior may be involved in relapse after exposure-based therapy for anxiety disorders.