Quantifying drivers’ comfort-zone and dread-zone boundaries in left turn across path/opposite direction (LTAP/OD) scenarios

The aim of this study is to quantify drivers’ comfort- and dread-zone boundaries in left-turn-across-path/opposite-direction (LTAP/OD) scenarios. These scenarios account for a large fraction of traffic fatalities world-wide. The comfort zone is a dynamic spatiotemporal envelope surrounding the vehicle, within which drivers feel comfortable and safe. The dread zone, a novel concept, describes a zone with a smaller safety margin that drivers will not voluntarily enter, but can push themselves into when conditions provide additional motivation (e.g., when hurried). Quantifying comfort- and dread-zone boundaries in the context of turning left before or after an oncoming vehicle has the potential to inform and improve both the design and driver acceptance of advanced driver assistance systems (ADAS) and autonomous vehicles.Using a within-subject design, a test-track experiment was conducted with drivers turning an instrumented vehicle left across the path of an oncoming vehicle. The oncoming vehicle was a self-propelled full-sized computer-controlled balloon vehicle going straight at a constant speed (50 km/h). The driver assumed full control of the instrumented vehicle approximately 20 m before the intersection and had to make the decision to turn left before or after the oncoming balloon vehicle. There were two experimental conditions, comfortable driving and hurried driving. Measures for each turn included post-encroachment time (PET), lateral acceleration, and self-reports of comfort and risk. Drivers consistently accepted shorter time gaps and higher lateral accelerations when hurried. We interpret these findings to suggest that drivers invoke two dynamic, contextually-defined safety margins. The first is the comfort-zone boundary, a limit which drivers do not voluntarily cross without extra motives. The second is the dread-zone boundary, a more distant limit which drivers do not voluntarily cross even with extra motives. Grouping the responses (high/low) to the driver behavior questionnaire (DBQ) improved the ability to predict the dread-zone boundary PET given the comfort-zone boundary PET.     

The divergent effects of fear and disgust on unconscious inhibitory control

Previous studies have shown that negative emotional distracters impair conscious inhibitory control. Recent research has shown that inhibitory control can be triggered unconsciously; therefore, in Experiment 1, we aimed to investigate whether negative emotional distracters affect unconscious inhibitory control. Furthermore, in Experiment 2, we examined whether fearful and disgusting distracters have differential effects on unconscious inhibitory control. Participants were instructed to perform a masked Go/No-Go task superimposed on a negative or neutral image cue (Experiment 1) or on a fearful, disgusting or neutral image cue (Experiment 2). Results showed that negative emotional distracters impaired unconscious inhibitory control; furthermore, disgusting distracters impeded unconscious inhibitory control when compared to fearful ones. This study is the first to provide evidence that fear and disgust may affect unconscious inhibitory control differently. These results expand the understanding of the relationship between emotions and inhibitory control.     

Assessing the perceived value of reflexive groups for supporting clergy in the Church of England

Little research has been conducted to assess the effectiveness of reflexive groups in supporting clergy. For this research, eight Church of England Bishops’ Advisors for Pastoral Care and Counselling were interviewed to ascertain the value of reflexive groups. These data were analysed using a thematic analysis. Two superordinate themes emerged: Contextual issues and Benefits, along with 20 subordinate themes. An online survey, consisting of questions that came from the Bishops’ Advisors data, was then sent to reflexive group participants (n?=?64), to see if their experiences matched those benefits identified by the Bishops’ Advisors. The data from 37 participants was statistically analysed. The data from both sets of participants reveal that reflexive groups are psychologically beneficial to clergy. The research concludes that the implementation of reflexive groups as a way of developing self-awareness and enculturating attitudes towards resilience and self-care is important to foster psychologically and spiritually healthy practice.     

Who,where, when: the demographic and geographic distribution of bicycle crashes in West Yorkshire

Factors associated with cycle safety, including international differences in injury and mortality rates, protective equipment and bicycle training, have been subject to increasing academic interest. Environmental variables associated with cycle safety have also been scrutinised, but few studies have focussed on geographical factors at the local level. This paper addresses this research gap by analysing a geo-referenced dataset of road traffic incidents, taken from the UK’s STATS19 dataset (2005–2012). We investigate incidents involving cyclists within West Yorkshire. This is an interesting case study area as it has an historically low cycling rate but very ambitions cycling plans following investment from the Department of Transport. West Yorkshire is found to be an unusually risky area for cyclists, with an estimated 53 deaths and 1372 serious injuries per billion kilometres cycled, based on census commuting statistics. This is roughly double the national average. This riskiness varies spatially and temporally, broadly in line with expectations from the previous literature. An unexpected result was that cycling seems to be disproportionately risky for young people in West Yorkshire compared with young people nationally. The case study raises the issue of potential negative health impacts of promoting cycling amongst vulnerable groups in dangerous areas. We conclude by highlighting opportunities for increasing cycling uptake via measures designed primarily to improve safety. The analysis underlying this research is reproducible, based on code stored at github.com/Robinlovelace/bikeR.     

Shared road is double happiness: Evaluation of a “Share the road” sign

A road sign with the text «Share the road» and a picture of a smiling cyclist and a passing car was evaluated in a before–after study with surveys among cyclists and car drivers. The sign was set up at two sites on a test road near Oslo in summer 2014. A similar road was used as a comparison. About two thirds of the participants on the test road had noticed the sign. The majority liked it and agreed with its message. Cyclists have more often noticed the sign than car drivers have and they were somewhat more positive towards the sign. Effects on self-reported behavior and the perceived behavior of others were evaluated by comparing changes from the before- to the after-period between test and comparison road. Self-reported behavior of both cyclists and car drivers has improved on the test road after the sign was set up, especially in overtaking situations, and these results are in accordance with how cyclists and car drivers perceived each other’s behavior. The general perception of other road users has improved as well. The results are most likely representative of similar roads with a large proportion of car traffic that is related to recreation and a relatively low level of conflict.     

Examining the role of working memory resources in following spoken instructions

This study investigated the involvement of working memory (WM) in following spoken instructions using concurrent tasks designed to disrupt components of the Baddeley and Hitch WM model [Baddeley, A. D., & Hitch, G. J. (1974). Working memory. In G. H. Bower (Ed.), The psychology of learning and motivation: Advances in research and theory (Vol. 8, pp. 47–89). New York, NY: Academic Press]. In each of three experiments, participants were presented with sequences of instructions to be either verbally repeated or physically performed using relevant objects. Backward counting, articulatory suppression, and eye closure during instruction encoding all disrupted recall, and also impaired recall of the linkage between movements and objects. Recall of actions was more accurate when they were physically enacted than repeated verbally, an advantage that was not affected by concurrent tasks. These findings indicate that aspects of the recall of spoken instructions including the binding of constituent movements to objects draw on multiple WM resources. The benefits of physical enactment of the instructed sequence do not appear to depend on the components of WM investigated in these studies.     

Investigating driving instructors: The mediating roles of driving skills in the relationship between organizational safety strategies and driver behaviours

The aim of the present study is to investigate the mediating roles of driving skills in relationship between organizational safety strategies and driver behaviours among driving instructors. Driving skills consist of perceptual-motor skills and safety skills. Driver behaviours are investigated under four factors: violations, errors, lapses, and positive driver behaviours. Participants were 132 driving instructors (108 male and 24 female). In order to measure organizational safety strategies, Organizational Safety Strategies Scale (OSSS) was developed for driving schools. Results of the principal component analyses yielded one-factor solution for OSSS. In order to test the indirect effects of organizational safety strategies on driver behaviours through driving skills, multiple mediation analyses were conducted by entering age and annual mileage as the control variables. As organizational safety strategies were stronger, driving instructors had higher levels of perceptual-motor skills, which resulted in higher violations. On the other hand, as organizational safety strategies were stronger, driving instructors had higher levels of safety skills, which resulted in less violations and lapses. It can be inferred that; organizational stronger safety strategies might have negative influences on road safety through higher perceptual-motor skills; whereas there can be positive influences on road safety through higher safety skills. In addition, both skills are related to organizational safety strategies. Hence, driving schools should consider the asymmetric relationship between perceptual-motor skills and safety skills while improving their safety strategies to decrease violations and lapses. Organizations might also develop interventions to balance the stated skills to increase road safety.     

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.     

The influences of listening and speaking on pedestrians' assessments of approaching vehicles

Research suggests a relationship between auditory distraction (such as environmental noises or a vocal cell phone conversation) and a decreased ability to detect and localize approaching vehicles. What is unclear is whether auditory vehicle perception is impacted more by distractions reliant on listening or distractions reliant on speaking (analogous to the two components of a vocal cell phone conversation). In two experiments, adult participants listened for approaching vehicle noises and while performing listening- and speaking-based secondary tasks. Participants were tasked with identifying when they first detect an approaching vehicle and when they no longer felt safe to cross in front of the approaching vehicle. For both experiments, the speaking task resulted in significantly later detection of approaching vehicles and riskier crossing thresholds than in the no-distraction and listening conditions. The listening secondary task significantly differed from the control condition in experiment 1, but not experiment 2. Overall, our results suggest auditory distractions, particularly those reliant on speaking, negatively impact pedestrian safety in situations where visual information is minimal. Results may provide guidance for future research and policy about the safety impacts of secondary tasks.     

Effects of a driver assistance system with foresighted deceleration control on the driving performance of elderly and younger drivers

It is imperative to enhance the safety of elderly individuals on the roads to ensure the quality of their daily life. Near-miss incidents or accidents at blind intersections often result from a conflict between the behaviors of the driver and of other road users (pedestrians and cyclists). The failure to search for potential conflict in the context of blind intersections is a concern pertaining to road safety. The proposed assistance system performs a proactive braking intervention to achieve a referenced velocity in uncertain situations, such as one in which an unobserved pedestrian might initiate a road crossing. The proactive braking intervention attempts to manage the potential risk of crashing with respect to covert hazards. Because an automated system may impair a human’s ability to perceive and respond to hazardous situations while driving, this study was designed to examine the effects of proactive braking intervention and visual support cues on elderly and younger drivers’ ability to respond to information about potentially hazardous situations. We conducted a public-road driving experiment involving 108 elderly and younger drivers from two non-overlapping age groups. It was observed that the vehicle slowdown realized through the proactive braking intervention enabled the drivers to perform safety confirmation near blind spots and caused them to be more sensitive to and wary of potential hazards. This approach could be effective not only for elderly drivers, but also for young or inexperienced ones.