Carl Pankok

Driver behavior in use of guide and logo signs under distraction and complex roadway conditions

White-on-blue logo signs on the sides of highways are typically used to notify drivers of food, gas, and lodging at an upcoming interchange. The current research assessed driver performance and attention allocation in a simulated freeway driving task when exposed to six-panel logo signs, nine-panel logo signs, mileage guide signs, and roadway work zones both with and without an in-car navigation device. The objective was to identify the impact of signage types on driver behavior under realistic driving conditions. Results revealed glance durations and fixation frequencies to guide signs to be significantly lower than with six-panel and nine-panel logo signs, but no differences were found between six-panel and nine-panel logo signs. There were also statistical differences among the independent variables for speed deviation and lane deviation, but magnitudes were not large enough to be considered practically significant in terms of driving safety. Overall, there were minor differences in sign processing time between logo signs and mileage guide signs, but such differences did not translate to degradations in vehicle control.

Testing and Validation of a Psychophysically Defined Metric of Display Clutter

Combinations of cockpit display features may lead to increased pilot perceptions of clutter. This research sought to capture pilot perceptions of display clutter associated with primary flight display features during a vertical takeoff and landing scenario and to validate a multidimensional measure of clutter previously developed for a fixed-wing environment. Sixteen active fixed-wing pilots were recruited for the study that used a simulator configured as a vertical takeoff and landing aircraft. A factor analysis was used to reduce the number of subdimensions of the clutter measure based on previous ratings data. The simplified measure revealed an increase in the number of active display features to cause an increase in perceived clutter. Displays including synthetic vision system features were perceived as significantly more cluttered than those without. Although a tunnel (highway in the sky) feature also contributed to clutter, pilots achieved higher navigation system failure detection rates when the fe...

The role of driver age in performance and attention allocation effects of roadway sign count, format and familiarity

White-on-blue logo signs are used to inform drivers of food, gas, lodging, and attraction businesses at highway interchanges. In this study, 60 drivers were asked to look for food and attraction targets on logo signs while driving in a realistic freeway simulation. The objective of the study was to quantify effects of the number of sign panels (six vs. nine), logo familiarity (familiar vs. unfamiliar), logo format (text vs. pictorial), and driver age (young, middle, and elderly) on performance, attention allocation and target identification accuracy. Results revealed elderly drivers to exhibit worse performance in comparison to middle-age and young groups even though they adopted a more conservative driving strategy. There was no significant effect of the number of panels, logo familiarity, and logo format on driver performance or attention allocation. In target identification, drivers were more accurate with familiar or text-based panels appearing in six-panel signs.

The effects of interruption similarity and complexity on performance in a simulated visual-manual assembly operation

The objective of the study was to assess the effects of interruption task similarity and complexity on performance of a simulated industrial assembly operation. Eighteen participants performed a simulated industrial assembly operation, including one trial with no interruption and eight others presenting an interruption task. Interruption conditions comprised a full crossing of task similarity to the primary assembly operation (similar, dissimilar) and complexity (simple, complex) with replication for each participant. Order of condition presentation was randomized. Findings revealed greater time to return to primary visual-manual assembly performance after a similar task interruption. Results also indicated complex interruptions may promote cognitive arousal that increases productivity following assembly interruptions. The majority of results are explained in terms of the Activation-Based Memory for Goals model. Findings provide some guidance for interruption management protocol design for workers engaged in procedural visual-manual assembly operations.

The Effect of Physical Workload and Modality of Information Presentation on Cognitive Inhibition in Highly Fit Young Males

OCCUPATIONAL APPLICATIONS This study presents an experiment assessing the interaction between physical task load and modality of information presentation on cognitive task performance. Results indicated that males of equivalent high fitness, between the ages of 18 and 25, can perform complex cognitive tasks reliably well while performing a concurrent physical task requiring up to 70% of aerobic capacity. Furthermore, results revealed that participants respond slightly more quickly to visual stimuli than auditory stimuli but are equally adept at inhibiting responses presented via either modality. These results are applicable to the design of information displays for information processing tasks as part of occupations requiring simultaneous worker physical performance, such as soldiers in combat situations, firefighters in emergency rescue, police officers in security patrols on foot, etc.TECHNICAL ABSTRACT Background: Many occupations require workers to perform cognitive tasks while concurrently performing a physical task, such as a soldier taking orders while running to a helicopter evacuation point or a firefighter navigating through a burning building. Diverse personal factors have been identified to influence the effect of physical workload on cognitive performance; however, the literature presents some contradictions, and findings appear heavily dependent on participant sample characteristics, physical task type, and cognitive task type. Purpose: The purpose of this study was to assess the interaction between physical workload and modality of information presentation on performance of a concurrent cognitive task by highly fit young males. Methods: Twenty-four highly fit males between the ages of 18 and 25 completed the experiment. Participants ran on a treadmill at one of three physical exertion levels (0%, 50%, and 70% of maximal oxygen uptake [VO2max]). Levels were selected based on a previously-defined “optimal range” of 40%–55% VO2max for facilitating concurrent cognitive performance. Participants were exposed to exertion below, within, or above the optimal range for 8 minutes in each trial while concurrently performing a stop-signal task with stimuli presented either visually or aurally. Accuracy, response time, stop-signal reaction time, and perceived cognitive workload were recorded. Results: Physical exertion level did not appear to have a significant effect on responses with the exception of a decrease in accuracy that approached significance (p < 0.10). Stimulus modality had a significant effect, with higher accuracy, lower response time, and lower stop-signal reaction time occurring with visual stimuli compared to auditory. The modality of the stop signal (an indicator that participants should inhibit a reaction) had no effect on any response. No significant interaction was found between physical exertion level and modality of information presentation on cognitive inhibition. Conclusions: Highly fit young males, when subjected to an acute bout of exercise requiring 70% VO2max or less and lasting 8 minutes or less, exhibit no negative effects on cognitive inhibition performance, but response time appears faster with visual versus auditory stimuli.

Influence of Flight Domain and Cockpit Display Dynamics on Pilot Perceived Clutter

Two analyses were conducted on three datasets from a series of aviation human factors experiments focused on the development and testing of measures of flight display clutter as well as the relation with flight task performance. The objectives of this study were to assess the effects of cockpit display dynamics and aircraft type on pilot perceptions of display clutter in simulated flight tasks through statistical analyses of the data gathered across the experimental studies. Comparisons were made on observations of pilots with comparable experience under similar headup or headdown display conditions. In general, this research demonstrated the clutter measures to be highly sensitive to aviation display and domain conditions. The findings also indicated that human information processing considerations in aviation display design coupled with attention to the visual characteristics of display features may provide an effective basis for mitigating potential effects of clutter on pilot performance.

An integrated measure of display clutter based on feature content, user knowledge and attention allocation factors

Abstract Existing measures of display clutter in the literature generally exhibit weak correlations with task performance, which limits their utility in safety-critical domains. A literature review led to formulation of an integrated display data- and user knowledge-driven measure of display clutter. A driving simulation experiment was conducted in which participants were asked to search ‘high’ and ‘low’ clutter displays for navigation information. Data-driven measures and subjective perceptions of clutter were collected along with patterns of visual attention allocation and driving performance responses during time periods in which participants searched the navigation display for information. The new integrated measure was more strongly correlated with driving performance than other, previously developed measures of clutter, particularly in the case of low-clutter displays. Integrating display data and user knowledge factors with patterns of visual attention allocation shows promise for measuring display clutter and correlation with task performance, particularly for low-clutter displays. Practitioner Summary: A novel measure of display clutter was formulated, accounting for display data content, user knowledge states and patterns of visual attention allocation. The measure was evaluated in terms of correlations with driver performance in a safety-critical driving simulation study. The measure exhibited stronger correlations with task performance than previously defined measures.

Influence of Task Knowledge and Display Features on Driver Attention to Cluttered Navigation Displays

Two experiments were conducted to assess the effect of display clutter on driver attention allocation for highand low-clutter in-vehicle navigation displays. Participants were asked to respond to navigation queries in a static, presentation-based experiment and a dynamic, driving simulator experiment. Results revealed differential associations between clutter and attention allocation such that stronger correlations were exhibited in the presentation-based experiment. Those measures of display clutter focusing on display features and data (i.e., bottom-up factors) had stronger correlations with attention allocation than measures focusing on user task knowledge or familiarity (i.e., top-down factors). The findings suggest that humans adjust search strategies to account for competing demands of multiple tasks in such a way that any effect of clutter on driver attention is minimized, and that bottom-up influences of clutter have a stronger association with driver attention allocation than top-down influences.

Driver performance and attention allocation in use of logo signs on freeway exit ramps

The objective of this research was to quantify the effects of driver age, ramp signage configuration, including number of panels, logo format and sign familiarity, on driver performance and attention allocation when exiting freeways. Sixty drivers participated in a simulator study and analysis of variance models were used to assess response effects of the controlled manipulations. Results revealed elderly drivers to demonstrate worse performance and conservative control strategies as compared to middle-aged and young drivers. Elderly drivers also exhibited lower off-road fixation frequency and shorter off-road glance durations compared to middle-aged and young drivers. In general, drivers adopted a more conservative strategy when exposed to nine-panel signs as compared to six-panel signs and were more accurate in target detection when searching six-panels vs. nine and with familiar vs. unfamiliar logos. These findings provide an applicable guide for agency design of freeway ramp signage accounting for driver demographics.

Information Content Requirements for Remote Pilot Handover of Control of Unmanned Aircraft Systems in the National Airspace

The objective of the work is to develop recommendations to support the development of information content requirements for integrating unmanned aircraft systems (UAS) into the National Airspace System (NAS). The focus of the work relates to handover of control where positive control of the aircraft is transferred from one crew to another. We reviewed the human factors literature and handover corollaries that exist in the current NAS. We developed a structured approach to identifying information requirements that included consideration of technological context, and then addressed task analysis, human-automation function allocation, and information availability. UAS pilot subject matter expert feedback was leveraged throughout the process. We provide recommendations for the technological and automation capabilities required for safe handover of control in the NAS, and associated information requirements. We discuss how our method provides a structured basis for making design decisions for complex, safety-critical systems.