Glance Duration Research Articles

Effects of Hybrid Interface on Ecodriving and Driver Distraction

Hybrid interfaces are emerging in-vehicle technologies that have received minimal research attention in the literature concerning potential impacts on driver performance. Hybrid interfaces have the potential to improve driver fuel efficiency but also to distract drivers. Participants drove a number of urban and suburban routes in the University of Calgary Driving Simulator while interacting with a hybrid interface and attempting to drive fuel efficiently. A within-subjects design was used and each participant drove with and without the hybrid interface. With the hybrid interface, significant reductions in acceleration from a stop were observed when compared with driving without the hybrid interface. Participants spent significantly less time looking to the road ahead while driving with the interface than without it. The duration of participant eye glances to the interface did not exceed 1.6 s; however, drivers tended to combine glances to the interface and speedometer. This combination resulted in several glance durations above 1.6 s without looking back to the road ahead. Balancing ecodriving benefits with driver distraction costs is discussed.

Evaluating the Visual Demand of In-Vehicle Information Systems

In-vehicle information systems (IVIS) provide a variety of driver support and infotainment functionality; however, there is a growing concern that the resulting engagement with IVIS could present significant sources of distraction to drivers. This paper summarises the PhD thesis of Dr Ainojie Alexander Irune, which was awarded at the University of Nottingham in December 2009. The primary aims of the research were to develop a framework to aid the selection of an appropriate HF/HCI method, for use at particular stages in the design process, and to develop a novel method (with a focus on glance duration) for assessing the visual demand afforded by IVIS. Five empirical studies are reported in the thesis. In the first study, interviews were conducted with subject experts and the results were combined with the literature to provide guidance regarding the appropriate use of human factors methods. The remaining four studies present an iterative development of a novel method capable of predicting the visual demand imposed by an IVIS.

Attention for emotional facial expressions in dysphoria: An eye-movement registration study

Former research demonstrated that depression is associated with dysfunctional attentional processing of emotional information. Most studies examined this bias by registration of response latencies. The present study employed an ecologically valid measurement of attentive processing, using eye-movement registration. Dysphoric and non-dysphoric participants viewed slides presenting sad, angry, happy and neutral facial expressions. For each type of expression, three components of visual attention were analysed: the relative fixation frequency, fixation time and glance duration. Attentional biases were also investigated for inverted facial expressions to ensure that they were not related to eye-catching facial features. Results indicated that non-dysphoric individuals were characterised by longer fixating and dwelling on happy faces. Dysphoric individuals demonstrated a longer dwelling on sad and neutral faces. These results were not found for inverted facial expressions. The present findings are in line with the assumption that depression is associated with a prolonged attentional elaboration on negative information.

In-Vehicle Glance Duration

In general, the unsafe conditions that are likely to produce a motor vehicle crash reside not at the mean of a given distribution (in other words, under typical conditions), but rather in the tails of the distribution. For example, an unusually slow response to a traffic obstacle, rather than an average response, may result in a collision. Although that situation means that crashes are the exception and not the norm, it has implications for how safety-critical data are approached and handled. In this current paper, experimental data collected in a driving simulator are used to demonstrate how an analysis of the average glance durations to an in-vehicle display might lead to different conclusions about safety compared with an alternative analysis of the tail end of the distribution. In addition, a model of crash risk based on the distribution of in-vehicle glances is described, as well as several characteristics of the traffic environment.

Identification of Real-Time Diagnostic Measures of Visual Distraction With an Automatic Eye-Tracking System

This study was conducted to identify eye glance measures that are diagnostic of visual distraction. Visual distraction degrades performance, but real-time diagnostic measures have not been identified. In a driving simulator, 14 participants responded to a lead vehicle braking at -2 or -2.7 m/s2 periodically while reading a varying number of words (6-15 words every 13 s) on peripheral displays (with diagonal eccentricities of 24 degrees, 43 degrees, and 75 degrees). As the number of words and display eccentricity increased, total glance duration and reaction time increased and driving performance suffered. Correlation coefficients between several glance measures and reaction time or performance variables were reliably high, indicating that these glance measures are diagnostic of visual distraction. It is predicted that for every 25% increase in total glance duration, reaction time is increased by 0.39 s and standard deviation of lane position is increased by 0.06 m. Potential applications of this research include assessing visual distraction in real time, delivering advisories to distracted drivers to reorient their attention to driving, and using distraction information to adapt forward collision and lane departure warning systems to enhance system effectiveness.

Visual Sampling of In-Vehicle Text Messages

Emerging in-vehicle technology associated with radio data systems, satellite radio, navigation aids, and infotainment systems will expose drivers to an increasing amount of textual information. The visual demands of driving make it critically important to understand how characteristics of such information affect visual sampling of the roadway. This study used a medium-fidelity driving simulator to evaluate the effect of scroll control (manual or automatic), the number of lines displayed (one, two, or four), and scrolling strategy (line by line or page by page) on drivers’ visual sampling behavior of text messages. Fifteen men and 15 women aged 25 to 51 (mean 35.7, s.d. 7.5) participated. Consistent with previous models of sampling behavior, text message characteristics affected the number of glances much more strongly than the duration of glances, and drivers were able to protect driving performance even with a demanding secondary visual task. However, the number of lines of text displayed increased the mean glance duration, the variability of glance duration, and the number of glances greater than 2 s. Scrolling text line by line increased visual demand relative to scrolling page by page, particularly when scrolling is manually controlled by the driver. Manual control of scrolling by using a touch screen button led to greater visual demand compared with automatically scrolled text.

Methodology for Capturing Driver Eye Glance Behavior During In-Vehicle Secondary Tasks

Driving is a visual task; any driver behavior that takes the driver's visual attention from the driving environment is likely to increase the risk of a crash. Many new intelligent transportation systems telematics applications are now being installed in cars, and some of these may result in substantial degradation of visual attention. Accurately capturing driver eye glance behavior during the evaluation of these devices is critical to assessing the safety impact of engaging in secondary tasks while driving. The development of a methodology is reported; it reliably determines on-road and off-road eye glance duration by using video data collected during highway driving evaluation trials while drivers were engaged with secondary tasks. Human raters determined glance location and duration by detailed coding of the driver's eye movements on the videos. The raters agreed most of the time, but sufficient disagreement suggested that using the consensus of multiple raters significantly improved the reliability of ...

Visual Sampling of In-Vehicle Text Messages: Effects of Number of Lines, Page Presentation, and Message Control

Emerging in-vehicle technology associated with radio data systems, satellite radio, navigation aids, and infotainment systems will expose drivers to an increasing amount of textual information. The visual demands of driving make it critically important to understand how characteristics of such information affect visual sampling of the roadway. This study used a medium-fidelity driving simulator to evaluate the effect of scroll control (manual or automatic), the number of lines displayed (one, two, or four), and scrolling strategy (line by line or page by page) on drivers' visual sampling behavior of text messages. Fifteen men and 15 women aged 25 to 51 (mean 35.7, s.d. 7.5) participated. Consistent with previous models of sampling behavior, text message characteristics affected the number of glances much more strongly than the duration of glances, and drivers were able to protect driving performance even with a demanding secondary visual task. However, the number of lines of text displayed increased the mean glance duration, the variability of glance duration, and the number of glances greater than 2 s. Scrolling text line by line increased visual demand relative to scrolling page by page, particularly when scrolling is manually controlled by the driver. Manual control of scrolling by using a touch screen button led to greater visual demand compared with automatically scrolled text.

Methodology for Capturing Driver Eye Glance Behavior during In-Vehicle Secondary Tasks

Driving is a visual task; any driver behavior that takes the driver's visual attention from the driving environment is likely to increase the risk of a crash. Many new intelligent transportation systems telematics applications are now being installed in cars, and some of these may result in substantial degradation of visual attention. Accurately capturing driver eye glance behavior during the evaluation of these devices is critical to assessing the safety impact of engaging in secondary tasks while driving. The development of a methodology is reported; it reliably determines on-road and off-road eye glance duration by using video data collected during highway driving evaluation trials while drivers were engaged with secondary tasks. Human raters determined glance location and duration by detailed coding of the driver's eye movements on the videos. The raters agreed most of the time, but sufficient disagreement suggested that using the consensus of multiple raters significantly improved the reliability of the resulting eye glance data.

On the highway measures of driver glance behavior with an example automobile navigation system

An over-the-road study of visual–manual destination entry using an example original equipment GPS-based navigation system was accomplished in traffic on urban streets and motorways. The evaluation used typical drivers, and a vehicle instrumented to record driver eye glances and fixations, driver control inputs, and lateral lane position. The primary task was to drive in a safe manner, in traffic, while maintaining speed and lateral lane position. As a secondary task, the drivers entered successive destinations while driving, using a touchscreen, and at their own pace. They were told there was no need to enter the destination quickly. Results are shown for driver glance behavior, lane keeping performance, and subjective ratings. Overall, the drivers were able to accomplish the destination entry tasks with acceptably short glance durations, acceptable total task times, and with satisfactory subjective ratings for ease of entry.

Impact of Video Advertising on Driver Fixation Patterns

To assess driver distraction because of video advertising signs, eye fixation data were collected from subjects who passed four video advertising signs, three at downtown intersections and one on an urban expressway. On average, drivers glanced at the signs on 45% of the occasions on which the signs were present. When drivers looked, they made 1.9 glances, on average, with an average duration per glance of 0.48 s. The distribution of eye fixations on intersection approaches where video signs were visible was compared with that on approaches on which video signs were not visible. No significant differences were found in the number of glances made at traffic signals or street signs. On the video approach, a greater proportion of glances were made at the speedometer and rearview mirrors. Glances were made at short headways and occasionally in unsafe circumstances. In the downtown area, glances at static commercial signs were made at larger angles and at shorter headways than was the case for video signs. A comparison of the results with those of other studies showed that video signs were less likely to be looked at than traffic signs (about half the time versus virtually every time, respectively) and that individual average glance durations and total durations were similar to those found for traffic signs in rural environments. These results apply to particular video signs in particular environments. Another on-road study indicates that a video sign on a curve that is close to the line of sight and visible for an extensive period is particularly distracting.

A naturalistic visual scanning approach to assess selective attention in major depressive disorder

Cognitive biases in information processing play an important role in the etiology and maintenance of emotional disorders. A new methodology to measure attentional biases is presented; this approach encourages subjects to scan and re-scan images with different thematic content, while the pattern of their attentional deployment is continuously monitored by an eye-tracking system. Measures of attentional bias are the total fixation time and the average glance duration on images belonging to a particular theme. Results showed that subjects with depressive disorder ( n=8; Beck Depression Inventory Score⩾16) spent significantly more time looking at images with dysphoric themes than subjects in the control group ( n=9). Correlation analysis revealed that the differences between the fixation times of the two groups are significantly correlated with the valence ratings, but not with the arousal ratings of the images. The average glance duration on images with social, neutral and threatening themes were similar for both groups, while the average glance duration on images with dysphoric themes was significantly larger for subjects with depressive disorder. The above results suggest that subjects with depressive disorder selectively attend to mood-congruent material and that depression appears to influence the elaborative stages of processing when dysphoric images are viewed.

THE EFFECT OF CELLULAR PHONE USE ON DRIVING PERFORMANCE

Many experiments using driving simulators or real roads have shown that using a cellular phone while driving may cause an accident because it delays visual information processing by the driver. In this research, we examined the influence on driving performance of cellular phone use on a course that simulated streets. Driving conditions were driving only, listening to the car radio, hands-free cellular phone use and using a cellular phone with the left hand. Driving performance measurements included braking response time to the brake lights of a preceding car, eye movement, distance from the vehicle in front and lane observance. The subjects were 50 drivers, including ten driving instructors. The mean glance duration when manipulating a cellular phone was longer than when manipulating a hands-free set or car stereo. Braking reaction delay time increased in the following order: driving only, car radio, hands-free and, longest of all, cellular phone. When the cellular phone was used, car speed was slowest, and the distance from the vehicle in front became the longest. Glance duration other than to the front, indicating divided attention, was shortest during the cellular phone use and there were also fewer instances of eye movement. In the case of cellular phone use, stable driving appeared to be more difficult, as there was substantial steering wheel deflection. In this experiment, it was confirmed that use of a hands-free set is effective to some extent, but driving performance was poorer than with driving only. Even though different forms of in-vehicle information apparatus were used, a delay in information processing was consistently found.

A human factors evaluation of a novel display and control concept for in-vehicle audio systems: a case study

A real evaluation of two in-car audio systems was conducted. One system employed a novel steering column mounted set of controls for the main features of radio, cassette and compact disc player. The design was intended to minimise eyes off road and hands off steering wheel time. A multi-level usability analysis methodology was adopted, and a wide range of data captured to investigate whether control and display design influenced mental workload, visual behaviour and vehicle control in real traffic. A comparison was made with results obtained with a traditional audio system. The novel design involved a disassociation of controls located on a pod behind the steering wheel, and a separate display mounted at a point high in the centre of the dashboard. The new system was associated with the following safety-related indices: lower mental workload scores, reduced visual glance duration, and reduced driving conflicts.

Individual Differences and in-Vehicle Distraction While Driving: A Test Track Study and Psychometric Evaluation

The influence of individual differences on driver distraction was examined in this study. Sixteen (16) test participants were trained on destination entry procedures with four commercially available route guidance systems, as well as the dialing task on a commercially available wireless cellular telephone and on manually tuning an after-market car radio. The participants then drove an instrumented vehicle at approximately 45 mph on a 7.5 mile oval test track with very light traffic while concurrently engaging in various tasks with these devices. In-vehicle task completion time, average glance duration away from the road ahead, number of glances away from the road ahead, and number of lane exceedences were recorded. The participants were later given an automated battery of temporal visual perception and cognitive tasks. Performance on the test battery was then correlated to performance on the test track measures to determine the extent to which individual driver differences could account for observed performance differences. Analysis of these elementary test scores as predictors show low but consistent patterns of correlation to test-track performance measures.

Driving experience and time-sharing during in-car tasks on roads of different width

Earlier research has not found consistent differences between the way novices and experienced drivers allocate time between road and in-car tasks when average time spent on the latter is being considered. This study addresses the question of whether novices occasionally fail in supervisory control more often than experienced drivers. The influence of driving experience and road type on the allocation of visual attention was investigated by analysing the distribution of glance duration at in-car tasks for 23 experienced (life-time driving experience 50 000 – 2 000 000 km) and 24 inexperienced (life-time driving experience 400 – 15 000 km) drivers. The duration and number of glances were recorded while the participants changed a radio cassette, dialled a mobile phone or tuned the radio, while driving on a highway or motorway. The experienced drivers allocated their visual attention more adequately, here interpreted as attributed to their greater driving experience. The glance duration of the novices showed a larger variance, due to a greater percentage of short, possibly ineffective, and long, risky glances. None of the experienced drivers took glances longer than 3 s at the in-car task, but 29% of the novices did. The novices' long glances were also associated with large lateral displacement of the car. Drivers took longer glances on a motorway than on a highway, which supports the notion that drivers accommodate their glances to the time margins dictated by different traffic situations.

Developing Baseline Data on Heavy Vehicle Driver Visual Workload

This study focused on the development of baseline measures of driver visual allocation under normal operating conditions. Thirty licensed truck drivers drove an instrumented heavy truck over a 459 km fixed route in which road type and ambient lighting condition were varied. An on-board video recording system was used to record the subject's visual glances throughout the run. During the run subjects performed three driving tasks: open road driving, car following and in-cab tasks requested by the experimenter. Over all conditions, the mean time off the road was 1.01 s and the mean road scene glance duration was 2.18 s. The results indicated that road type and driving task were significant factors affecting driver visual workload indicators. Ambient light level was not a significant factor affecting the visual allocation of truck drivers.

Utility Assessment of Side Object Detection Systems for Heavy Trucks

Side object detection systems (SODS) alert drivers to the presence of traffic alongside their vehicle within a defined detection zone. Their intent is to reduce lane changing and merging collisions. The effect of right SODS on the safety related behavior of commercial vehicle drivers was examined in this study. Eight subjects drove a tractor-semitrailer equipped with four different sets of right SODS or mirrors. Subjects were tested with two right SODS (a radar-based system, and an ultrasonic-based system), a fender-mounted convex mirror, and, for comparison, standard side view mirrors. For each case, subjects drove the test vehicle through a set route for one day. The effect of these systems on driver behavior and the extent to which safety may be improved by implementing SODS were assessed based upon the correctness of responses and verbal response times to Right Clear questions, and upon subject glance fixations and durations. A debriefing questionnaire was used to acquire subjects' opinions about the SODS. Driver performance with SODS was not significantly improved over that observed with standard side view mirrors. Analysis of the correctness of responses to Right Clear questions showed that subjects' accuracy in assessing the traffic situation along the right side of the vehicle was not improved by the SODS, but was improved by the fender-mounted convex mirror. Verbal response times to Right Clear questions were significantly lower with the SODS and fender-mounted convex mirror than with standard mirrors. This difference may have resulted from a learning effect caused by presenting the standard mirrors first to each subject. Glance data showed that subjects only sometimes visually sampled the SODS displays. Responses to debriefing questionnaires indicated that subjects were receptive to the concept of SODS and very positive about the fender-mounted convex mirror. However, if SODS are to offer significant safety benefits in the future, more work is needed to refine their performance and design.

Nonverbal concomitants of enacted emotional intensity and positivity: Visual and vocal behavior1

AbstractThis study focused on how emotional expressions are implied through visual and vocal behaviors. The roles of proportion gaze, glance duration, and vocal loudness in expressing emotional positivity and intensity were examined. Emotional positivity, emotional intensity, and target of the communication were manipulated in a mixed design. Forty‐eight female subjects performed a liking or an anger message to a man and to a camera with strong and weak intensity. Videotaped responses were analyzed. Strong emotional intensity conditions evoked more direct gaze regardless of the message positivity or the target of the emotional expression. Longer glances and louder speech were associated with only intense negative emotional expression regardless of the target of the expression. The proportion gaze data support the view that eye contact serves as an intensifier of affective expression. Methodological considerations and questions about generalizability are discussed.