A simulator study of factors influencing drivers’ behavior at traffic lights

Drivers’ reactions to changing traffic lights have an impact on safety at intersections. We examined the influence of transient factors – more specifically time pressure and social context, both conducive to traffic-light violation – on behavior behind the wheel when a traffic light changes. We carried out an experiment on a driving simulator. The participants were 94 car drivers (53 males) with a mean age of 21.7 years. They drove under time pressure vs. no time pressure. At several intersections the participants were alone (no other drivers present), whereas at several other intersections they were behind a line-up of vehicles, the last of which ran the yellow light (other drivers present). As expected, time pressure and social context (presence of other drivers) increased participants’ risky behaviors while approaching, and going through traffic lights, as well as undesirable rapid accelerations when the signal changes to green. The effect of time pressure on yellow-light running was not mediated by approach speed, which showed that participants in a hurry were likely to run lights intentionally. The results are interpreted in view of proposing effective measures for reducing yellow-light running and rapid accelerations at traffic lights.     

The perception of speaking rate using visual information from a talker’s face

It has been well documented that listeners are able to estimate speaking rate when listening to a talker, but almost no work has been done on perception of rate information provided by looking at a talker’s face. In the present study, the method of magnitude estimation was used to collect estimates of the rate at which a talker was speaking. The estimates were collected under four experimental conditions: auditory only, visual only, combined auditory-visual, and inverted visual only. The results showed no difference in the slope of the functions relating perceived rate to physical rate for the auditory only, visual only, and combined auditory-visual presentations. There was, however, a significant difference between the normal visual-only and the inverted-visual presentations. These results indicate that there is visual rate information available on a talker’s face and, more importantly, suggest that there is a correspondence between the auditory and visual modalities for the perception of speaking rate, but only when the visual information is presented in its normal orientation.     

Drivers’ visual attention: A field study at intersections

Crossing a road intersection, a driver must collect visual information from various locations. The allocation of visual attention, which allows this collection, mainly relies on top-down processes. This study focuses on three top-down factors which influence the collection of visual information: the value of visual information for the ongoing task, their bandwidth, and the familiarity with the environment. These factors are studied according to the priority rules at intersections (Give way, Stop or Priority), the expected traffic density (Lower or Higher) and the number of passages (First or Second passage). Fourteen participants were installed in an instrumented vehicle equipped with an eye-tracker. They drove during 1h45 along a 80-km long route, mainly on rural roads, which included 19 intersections. Visual attention was studied by means of the head and gaze horizontal eccentricity. Effects were found for each of the three factors, in agreement with Wickens’ theoretical framework and with previous studies, despite the important variability in the data due to the experimental situation.     

Does unconscious information affect cognitive activity?: a study using experimental priming

In a series of three experiments the influence that information unrecognised by the subjects has on the effectiveness of occurring cognitive activity is studied. With this aim 3 types of stimulus were compared which for one reason or another were not afforded sufficient attention, namely: unconscious meanings of polysemantic information, stimuli presented at the subliminal level, and intentionally ignored distractors. All the listed types of stimuli are united in that the subjects were not able to give an account of them, i.e., these stimuli were not processed attentively. It is assumed that each of the types of stimuli studied is in actuality perceived, which can be judged by the impact they have on occurring cognitive activity. The purpose of the present research is the comparison of this impact: apart from the determination of the impact of unperceived stimuli on the information directly associated with them (priming-effect registration), also identified is the presence/absence of an overall interference effect rendered by the unperceived stimuli on the performance of occurring cognitive activity. To this end, each experiment had a control condition the aim of which was the creation of the possibility for the subjects to perceive stimuli unnoticed under experimental conditions. An experimental priming paradigm was used in combination with image-classification and lexical-decision tasks. The results of the experiments conducted demonstrate that all types of stimuli 'slipping the attention' are assimilated, but their effect on occurring cognitive activity is varied. Thus, subliminally presented information aids, and distractors, on the contrary, hinder the solution of tasks associated with them, whereas unperceived meanings of polysemantic information hinder not only the solution of the tasks directly associated with them, but also the performance of any other cognitive activity for which they serve as a context. The effect of subliminal stimuli on occurring cognitive activity in the present research is explained by the spreading activation in the memory, the effect of distractors--by the inhibition of irrelevant representations in the information-processing system. For an explanation of the consequence of unperceived meanings of polysemanticity, not only an inhibition model was used, but also an unconscious negative choice model which assumed the necessity of making a special decision on non-perception.     

Measuring information demand of a dynamic in-vehicle display while driving – A study evaluating the MARS (Masking Action Relevant Stimuli) method

The MARS (Masking Action Relevant Stimuli) method assesses information demand for dynamic stimuli while driving. An action relevant stimulus is masked and the driver presses a button to unmask the stimulus for a limited period. We interpreted button presses as information demand. Following our previous research (Rittger, Kiesel, Schmidt, & Maag, 2014), the current study further evaluates the method. We applied the MARS method to a dynamic in-vehicle display containing recommendations from a traffic light assistant. In a driving simulator, drivers approached intersections with different traffic light phasing. The display either presented simple or complex information. In half of the drives, the participants used the MARS method. The study had a full within subjects design and fixations were recorded in all conditions. The results showed that the information demand varied according to the information in the display and the traffic light phase. A comparison of button presses with fixations showed that one unmasking interval came along with one fixation on the display. As a conclusion, the MARS method can distinguish between conditions with high and low information demand for the display. Button presses relate to fixations on the display. Hence, the MARS method is a promising tool to assess the information demand in dynamic environments and can be applied as an extension or alternative for eye tracking.     

Effect of driving inactivity on driver’s lateral positioning control: A driving simulator study

Overall on-road driving skill is a cumulated acquisition of driving skills learned during training period and furthered tempered with post-licensing driving exposure on the roads. Training serves to develop a person’s basic driving skills to operate safely on the roads at first, while subsequent on-road driving hones the driving skills further. Inactivity from on-road driving can result in deterioration of driving skills. Particularly for the case of inactivity immediately following licensure, which is not uncommon in Singapore, the learned skills can degrade rapidly. This research aims to examine the effect of driving inactivity on the learned driving skill, i.e. lateral positioning control, specifically for young-inexperienced drivers. A series of experiments were conducted on a driving simulator for different subject groups involving active driver, novice driver (freshly-licensed driver), inactive driver (never ever drive upon licensure), and no licence subjects. The participants drove through a stretch of expressway under free-flow conditions, and lane positioning control was monitored. It is found that without on-road driving exposure, driving skills like maintenance of lane positioning control in terms of lane wandering and lane encroachment may deteriorate after some periods of inactivity, i.e. 3 months. The deterioration varies at different rate, with faster deterioration for more complex tasks. The skills level can regress close to un-trained level for complex driving tasks. The findings also suggest that on-road driving exposure is needed to not only retain but also to improve the lane positioning control skills.     

The importance of gestural communication: a study of human–dog communication using incongruent information

We assessed how water rescue dogs, which were equally accustomed to respond to gestural and verbal requests, weighted gestural versus verbal information when asked by their owner to perform an action. Dogs were asked to perform four different actions (“sit”, “lie down”, “stay”, “come”) providing them with a single source of information (in Phase 1, gestural, and in Phase 2, verbal) or with incongruent information (in Phase 3, gestural and verbal commands referred to two different actions). In Phases 1 and 2, we recorded the frequency of correct responses as 0 or 1, whereas in Phase 3, we computed a ‘preference index’ (percentage of gestural commands followed over the total commands responded). Results showed that dogs followed gestures significantly better than words when these two types of information were used separately. Females were more likely to respond to gestural than verbal commands and males responded to verbal commands significantly better than females. In the incongruent condition, when gestures and words simultaneously indicated two different actions, the dogs overall preferred to execute the action required by the gesture rather than that required verbally, except when the verbal command “come” was paired with the gestural command “stay” with the owner moving away from the dog. Our data suggest that in dogs accustomed to respond to both gestural and verbal requests, gestures are more salient than words. However, dogs’ responses appeared to be dependent also on the contextual situation: dogs’ motivation to maintain proximity with an owner who was moving away could have led them to make the more ‘convenient’ choices between the two incongruent instructions.     

Spatial working memory maintenance: Does attention play a role? A visual search study

Recent studies have proposed that a common mechanism may underlie spatial attention and spatial working memory. One proposal is that spatial working memory is maintained by attention-based rehearsal [Awh, E., Jonides, J., & Reuter-Lorenz, P. A. (1998). Rehearsal in spatial working memory. Journal of Experimental Psychology: Human Perception and Performance, 24(3), 780-790], and so a spatial attention shift during the retention interval of a spatial location should impair its memory performance. In the present study, participants engaged in single-item, parallel or serial search tasks while remembering a spatial location. Although memory tended to bias all searches, the need for an attentional shift during the retention interval impaired memory performance only in single-item search, but not in other searches. These findings suggest that previous evidence for the attention-based rehearsal account does not generalize to visual search. Results are discussed with regard to the relationship between spatial attention and spatial working memory.     

Poor readers’ use of orthographic information in learning to read new words: A visual bias or a phonological deficit?

In this study, we examined the ability of 11-year-old poor readers and reading age controls to learn new print vocabulary. It was found that the poor readers were slower than the controls to learn to read a set of nonwords accurately but that, when asked to pick out the nonwords in a visual recognition memory task, they reached criterion much more quickly than did the controls. However, when the groups were compared on auditory recall of the items being learned, the poor readers were at a disadvantage. Thus, the poor readers developed a visual store for the nonwords more quickly than did the controls but were slower to establish phonological representations for the nonwords. It was concluded that the poor readers were slower to establish a form of sight word reading that was well underpinned in memory by connections between the letters in the spelling and the phonemes in the pronunciation, suggesting that they had a greater reliance on an orthographic-semantic pathway in word recognition than did the controls.     

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.     

Effect of auditory in-vehicle warning information on drivers’ brake response time to red-light running vehicles during collision avoidance

There is usually a high red-light running (RLR) collision rate at signalized intersections because of the unpredictability of dangerous RLR vehicles traversing intersections illegally. The RLR collision warning systems can help drivers be aware of the red-light running (RLR) vehicles and take collision avoidance actions timely. The objective of this paper is to evaluate the effects of auditory warning information on brake response time (RT) to red-light running vehicles during the collision avoidance process based on a driving simulator experiment. Warning status (e.g., warning vs. no warning), warning lead time (3 s vs. 5 s) and warning content (directional information vs. undirectional information) were considered to examine the effectiveness of the RLR collision warning system under different conditions. The experiment results showed that the auditory warning information can effectively reduce brake RT and collision occurrence rate and RT is the most influential variable on the collision occurrence. Although early warning is more effective than late warning in reducing brake RT and collision rate, the late warning can still lower the collision rate by 37%. However, the directional warning information did not have apparent advantages over the undirectional warning information. The findings of this study are helpful for the designers of RLR collision warning systems to enhance the effectiveness of the systems’ application on traffic safety.     

Is handedness recognition automatic? A study using a Simon-like paradigm

The authors used a modified Simon task (J. R. Simon, 1969) to assess the automatic recognition of handedness. Participants responded to the color of a circle in the center of the photograph of a right or a left hand, displayed in the center of the computer screen. A regular Simon effect was found for back views, whereas a reverse Simon effect was found for palm views. This pattern of results was found when the forearm was present (Experiment 2), when 1 finger at a time was rendered invisible (Experiment 3), and when the hands were connected to a body image (Experiment 4). When the hands were cut at the wrist, no effect emerged (Experiment 1). These findings suggest an automatic encoding of the relative position of the hand in relation to the body (imaginary or real) rather than the automatic encoding of handedness.     

Drivers’ performances and their subjective feelings about their driving during a 40-min test on a circuit versus a dynamic simulator

Car manufacturers expect driving simulators to be reliable research and development tools. Questions arise, however, as to whether drivers’ behavior on simulators exactly matches that observed when they are driving real cars. Drivers’ performances and their subjective feelings about their driving were compared between two groups during a 40-min driving test on the same circuit in a real car (n = 20) and a high-fidelity dynamic simulator (n = 27). Their speed and its variability, the braking force and the engine revolutions per minute (rpm) were recorded five times on a straight line and three times on a curve. The differences observed in these measurements between circuit driving (CD) and simulator driving (SD) from the 6th to 40th minute showed no significant changes during the drive. The drivers also completed the NASA Raw Task Load Index (NASA RTLX) questionnaire and the Simulator Sickness Questionnaire (SSQ) and estimated the ease and standard of their own driving performances. These subjective feelings differed significantly between the two groups throughout the experiment. The SD group’s scores on the NASA RTLX and SSQ questionnaires increased with time and the CD group’s perceived driving quality and ease increased with time, reaching non-significantly different levels from their usual car driving standards by the end of the drive. These findings show the existence of a fairly good match between real-life and simulated driving, which stabilized six minutes after the start of the test, regardless of whether the road was straight or curved. These objective findings and subjective assessments suggest possible ways of improving the match between drivers’ performances on simulators and their real-life driving behavior.     

“Universal reason” as a local organizational method: Announcement of a study

This article announces an ethnomethodological study of the formal analytic practices of Tibetan philosophers engaged in the collaborative work of producing correct philosophical debates. Tibetan scholar-monks address themselves to the work of sustaining an argument, providing formal warrants for authorizing truth and correctness, objectivating their accounts and disengaging those accounts from their local organizational practices. At the same time, it is the concern of the Tibetans' dialectics to avoid naive acceptance of reified accounts. The announced study proposes to describe their philosophical activities and to locate what originality may affect resolving the tension between formal analytic work and philosophical insight into truth.     

‘We’ve shared a lifetime with one another’: using reflective visual/verbal journals to develop graduate student relationships

The success of graduate students relies on factors beyond mere cognitive ability, with fostering peer and professional relationships as definitive influences on achievement. Research shows that positive faculty/student relationships are a significant factor in the success of graduate students and that art-making is an effective way to encourage the reflective thinking needed to nurture these relationships. In this article, we examine the relationship between arts informed pedagogy, specifically the use of a visual/verbal journal, and the formation of graduate relationships. The majority of the students in this collaborative inquiry entered their doctoral program at the same time the research class began and all engaged in an artfully imagined introduction to qualitative research course.     

Measuring drivers’ takeover performance in varying levels of automation: Considering the influence of cognitive secondary task

Mixed control by driver and automated system will remain in use for decades until fully automated driving is perfected. Thus, drivers must be able to accurately regain control of vehicles in a timely manner when the automated system sends a takeover request (TOR) at its limitation. Therefore, determining the factors that affect drivers’ takeover quality at varying levels of automated driving is important. Previous studies have shown that visually distracting secondary tasks impair drivers’ takeover performance and increase the subjective workload. However, the influence of purely cognitive distracting secondary tasks on drivers’ takeover performance and how this influence varies at different levels of automation are still unknown. Hence, a 5 (driving modes) × 3 (cognitive secondary tasks) factorial design with the within-subject factors was adopted for this driving simulator experiment. The sample consisted of 21 participants. The participants’ subjective workloads were recorded by the NASA-Task Load Index (NASA-TLX). Results showed that compared to manual driving conditions, the drivers’ subjective workloads were significantly reduced in both partially and highly automated driving conditions, even with a TOR, confirming the benefit of the automated driving system in terms of reducing the driving workload. Moreover, the drivers exhibited a lower takeover behavior quality at high levels of automation than manual driving in terms of increased reaction time, abnormal performance, standard deviation of lane position, lane departure probability, and reduced minimum of time to collision. However, at the highly automated driving condition, the drivers’ longitudinal driving safety and ability to follow instructions improved when performing a highly cognitive secondary task. This phenomenon possibly occurred because automated driving conditions lead to an underload phenomenon, and the execution of highly cognitive tasks transfers drivers into moderate load, which helps with the drivers’ takeover performance.