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Objective: An evaluation study was conducted to answer the question of which system properties of night vision enhancement systems (NVESs) provide a benefit for drivers without increasing their workload. Background: Different infrared sensor, image processing, and display technologies can be integrated into an NVES to support nighttime driving. Because each of these components has its specific strengths and weaknesses, careful testing is required to determine their best combination. Method: Six prototypical systems were assessed in two steps. First, a heuristic evaluation with experts from ergonomics, perception, and traffic psychology was conducted. It produced a broad overview of possible effects of system properties on driving. Based on these results, an experimental field study with 15 experienced drivers was performed. Criteria used to evaluate the development potential of the six prototypes were the usability dimensions of effectiveness, efficiency, and user satisfaction (International Organization for Standardization, 1998). Results: Results showed that the intelligibility of information, the easiness with which obstacles could be located in the environment, and the position of the display presenting the output of the system were of crucial importance for the usability of the NVES and its acceptance. Conclusion: All relevant requirements are met best by NVESs that are positioned at an unobtrusive location and are equipped with functions for the automatic identification of objects and for event-based warnings. Application: These design recommendations and the presented approach to evaluate the systems can be directly incorporated into the development process of future NVESs.

Thirty-six pilots (31 men, 5 women) were tested in a flight simulator on their ability to intercept a pathway depicted on a highway-in-the-sky (HITS) display. While intercepting and flying the pathway, pilots were required to watch for traffic outside the cockpit. Additionally, pilots were tested on their awareness of speed, altitude, and heading during the flight. Results indicated that the presence of a flight guidance cue significantly improved flight path awareness while intercepting the pathway, but significant practice effects suggest that a guidance cue might be unnecessary if pilots are given proper training. The amount of time spent looking outside the cockpit while using the HITS display was significantly less than when using conventional aircraft instruments. Additionally, awareness of flight information present on the HITS display was poor. Actual or potential applications of this research include guidance for the development of perspective flight display standards and as a basis for flight training requirements.

One of the aspects that cause an interactive vehicle simulator to differ from the real system is delay in the visual display. Because of this delay, the person in the simulator receives visual feedback of his control actions slightly later when compared with the real system, which can reduce the task performance. Compensation techniques can be applied to reduce the effects of delay. This article describes an algorithm that was implemented in a driving simulator for this purpose. Two experiments were carried out, in which subjects drove the simulator with and without compensation, to evaluate its effect on task performance and control effort. The results show that the display delay is counterbalanced by the compensation in an effective and efficient manner: when using the compensation, driving behaviour in the simulator has a better resemblance to that in the real vehicle.

A sequential or RAP COM (rapid communication) display was compared with a more conventional spatial display as participants monitored dynamically changing sets of three-digit numbers and responded to occasional target stimuli. In an effort to equate the stimulus-response compatibility of the two displays, we had participants respond to the targets with a chord keyboard in Experiment 1 and vocally in Experiment 2. We examined the influence of display duration on performance with the RAP COM and spatial formats by presenting stimuli at three different durations (400, 800, and 1200 ms). The influence of practice on performance with the RAP COM and spatial displays was also investigated. Participants responded to targets more quickly in the RAP COM than in the spatial displays at each of the three presentation durations and across more than 2000 trials of practice. Accuracy was influenced by the display presentation duration. Accuracy was higher for the RAP COM than for the spatial display at the 800-ms stimulus presentation duration in Experiment 1 and at the 800- and 1200-ms presentation durations in Experiment 2. The results are discussed in terms of the potential utility of RAP COM displays for complex, real-world systems.

Polygon displays compress information that would otherwise be conveyed by separate indicators into a single display in which each reading is represented by the distance of a polygon vertex from its center. The effect on detection of fault states of varying the number of polygon vertices from 4 to 20 in a display presented peripherally around a dynamic, simulated flight display was studied. Presence of the dynamic task reduced both speed and accuracy of response to the polygon display but did not significantly affect the pattern of response to differing numbers of vertices. All measures of performance were better with larger numbers of vertices. If the vertices are processed serially, more vertices require more processing time. Therefore, the result argues for holistic processing and implies that such information integration is beneficial to human performance in fault detection.

This paper describes a 2–1/2 year project concerning human factors and future driver-information systems. The project goals are to (1) develop human factors guidelines, (2) devise test methods for safety and ease of use, and (3) develop a model that predicts driver performance when using these systems. A literature review has been completed and focus groups that identified driver needs have been conducted. In addition, a method was developed to select the most beneficial systems using accident reduction, congestion relief, and driver needs/wants as the criteria. Consequently, car phones, navigation, traffic information, vehicle monitoring, and hazard warning systems were selected for further study. Preliminary versions of each have been designed and laboratory tests are in progress. Usability tests in a driving simulator and on the road are scheduled.

A survey was distributed and an experiment was performed to analyze two air traffic control (ATC) color-coded display formats: (1) the currently used plan view display format, and (2) a perspective display format. The results of both the survey and experiment were used to extract specific user requirements from which specifications could be applied to design a three-dimensional, dynamic, color-coded, perspective display for use in an ATC environment. The emphasis of the survey and current experiment focused on the air traffic controller's point of view in terms of cognitive workloads, task and information requirements, color preferences, and air traffic workloads relative to traffic density and complexity. Fifteen full-performance air traffic controllers performed three timed tasks: (1) resolve impending air traffic conflicts, (2) identify the callsigns of aircraft in the highest and lowest actual altitudes, and (3) reconstruct air traffic situations. Two levels of traffic density were crossed with two display types for six different ATC scenarios. The results indicated that for the conflict resolution task performance was faster for the perspective display format only in the lower density level, and performance was the same for both display types in the higher density level. Performance for altitude extraction task for both density levels was faster for the perspective display format than for the plan view display format. Performance was the same for the reconstruction task for both display types and both density levels. Finally, performance was faster for the conflict resolution task than for the altitude extraction task across both display types and both density levels.

This paper presents a cognitive analysis of a pilot's navigation task and describes an experiment comparing a new map display that employs the principle of visual momentum with the two traditional approaches, track-up and north-up. The data show that the advantage of a track-up alignment is its congruence with the egocentered forward view; however, the inconsistency of the rotating display hinders development of a cognitive map. The stability of a north-up alignment aids the acquisition of a cognitive map, but there is a cost associated with the mental rotation of the display to a track-up alignment for tasks involving the ego-centered forward view. The data also show that the visual momentum design captures the benefits and reduces the costs associated with the two traditional approaches.

OBJECTIVE: This experiment attempted to identify the features of air traffic geometry that would influence the difficulty and biases of pilots' conflict detection using a cockpit display of traffic information (CDTI). BACKGROUND: There was previously no systematic study on effects of such features on conflict detection using the CDTI. METHOD: Twenty-four pilots viewed dynamic encounters between their own aircraft and an intruder aircraft on a simulated CDTI; difficulty was varied by the intruder aircraft's distance and time to closest point of approach (CPA), relative speed, miss distance at CPA, approach side, and conflict angle. Participants estimated the intruder's location at, and its time to, CPA. Effects on three estimation error measures were explored: intruder's miss distance at CPA, orientation at CPA, and time to CPA. RESULTS: (a) Estimation errors increased with slower speeds, longer times to CPA, and longer distances to CPA and with longer miss distances at CPA; (b) the best performance occurred at a conflict angle of 90 degrees; (c) there was a bias to judge conflicts to be more risky than was actually the case; and (d) there was a "distance-over-speed" bias, such that two aircraft farther apart and converging rapidly were perceived as less risky than when they were closer to each other and converging at a slower rate, despite identical time to CPA. CONCLUSION: Pilots' conflict detection with CDTI was subject to various errors and biases, which has important safety implications. APPLICATION: The design of procedures, displays, and decision support tools for the free flight environment needs to take these human performance limitations into account. Language: en

In the first part of the reported research, 12 instrument-rated pilots flew a highfidelity simulation, in which air traffic control presentation of auditory (voice) information regarding traffic and flight parameters was compared with advanced display technology presentation of equivalent information regarding traffic (cockpit display of traffic information) and flight parameters (data link display). Redundant combinations were also examined while pilots flew the aircraft simulation, monitored for outside traffic, and read back communications messages. The data suggested a modest cost for visual presentation over auditory presentation, a cost mediated by head-down visual scanning, and no benefit for redundant presentation. The effects in Part 1 were modeled by multiple-resource and preemption models of divided attention. In the second part of the research, visual scanning in all conditions was fit by an expected value model of selective attention derived from a previous experiment. This model accounted for 94% of the variance in the scanning data and 90% of the variance in a second validation experiment. Actual or potential applications of this research include guidance on choosing the appropriate modality for presenting in-cockpit information and understanding task strategies induced by introducing new aviation technology.

The difficulty of mastering a two-axis, compensatory, manual control task was manipulated by introducing transport delays into the feedback loop of the controlled element. Realistic aircraft dynamics were used. Subjects' display was a simulation of an "inside-out" artificial horizon instrument perturbed by atmospheric turbulence. The task was to maintain straight and level flight, and delays tested were representative of those found in current training simulators. Delay compensations in the form of first-order lead and first-order lead/lag transfer functions, along with an uncompensated condition, were factorially combined with added delays. Subjects were required to meet a relatively strict criterion for performance. Control activity showed no differences during criterion performance, but the trials needed to achieve the criterion were linearly related to the magnitude of the delay and the compensation condition. These data were collected in the context of aircraft attitude control, but the results can be applied to the simulation of other vehicles, to remote manipulation, and to maneuvering in graphical environments.

The advantage of a head-up auditory display was evaluated in a preliminary experiment designed to measure and compare the acquisition time for capturing visual targets under two auditory conditions: standard one-earpiece presentation and two-earpiece three-dimensional (3D) audio presentation. Twelve commercial airline crews were tested under full mission simulation conditions at the NASA Ames Man-Vehicle Systems Research Facility advanced concepts flight simulator. Scenario software generated visual targets corresponding to aircraft that would activate a traffic collision avoidance system (TCAS) aural advisory; the spatial auditory position was linked to the visual position with 3D audio presentation. Results showed that crew members using a 3D auditory display acquired targets approximately 2.2 s faster than did crew members who used one-earpiece headsets, but there was no significant difference in the number of targets acquired.

We report two experiments in which different features of the display of multiple channels of information are varied in their proximity to one another. The display presents three indicators of aircraft stall danger (airspeed, flaps, and bank). On some trials the stall danger is estimated, requiring information integration. On other trials the value of individual indicators is estimated, requiring focused attention. In Experiment 1 the spatial proximity between indicators and their distinctiveness in color were manipulated. Spatial proximity had little effect on either focused attention or integration, whereas a distinct color code improved focused attention and disrupted integration. In Experiment 2 the three indicators were presented as a bar graph or were combined as features of an object display, either with or without color coding of the separate dimension. Relative to the bar graph display, the object display improved information integration but disrupted focused attention. The presence of color borders restored the focused attention accuracy, with a slight cost to response time.

This paper presents a review of the driving research literature in a search for evidence related to secondary task interference on driving. Driving studies employing secondary tasks fall into two broad categories: (a) studies concerned with driver workload, and (b) studies concerned with driver fatigue. A mjority of these studies lack a valid theoretical basis for the application of the secondary task technique and the particular choice of secondary task. Few of them examined mutual interference between secondary tasks and driving. Some studies, however, reported interference, implying the presence of resource competition. This should be of concern to equipment designers.

Ten men scanned cathode-ray-tube displays to search for designated target items. Search time increased with increasing display density, and was 50% faster when a 3-cps blink was imposed on items of the target class. The blinking of nontarget items was almost equally effective, indicating that blink can be used either as an inclusion or exclusion code. In comparison with steady, nonblinking displays, search time was not significantly different for displays in which all items blinked, or in which a random selection of items blinked. It is concluded that for visual search tasks of the kind reported here, there is no marked deleterious effect of blink coding on symbol legibility, and no marked interference attributable to irrelevant blink.

Previous investigations of static and dynamic acuity have shown only inconsistent relations between measures of these aspects of visual performance. In the present study, six static and six dynamic visual sensitivity measures were gathered on 49 persons aged 7 to 61 years (M = 31 years). Contrary to previous findings, it was determined that when treated as latent factors with multiple indices, static and dynamic sensitivity are significantly correlated (r = 0.52). Further, both measures show an age-related decline, with dynamic sensitivity the most affected. Results have a bearing on models of spatial vision, efforts to determine screening procedures for performance in natural settings, and hypotheses concerning ontogenic decline in visual function.

This on-road study examined the effect of the positioning of an attentionally demanding in-car task on the driver's ability to detect the approach of a decelerating car ahead. Twelve participants aged between 19 and 27 years with an average of 18 170 km life-time driving experience drove 20 and 40 m behind a vehicle which decelerated from 50 km/h at 0.7 m/s2 without braking. Detection thresholds for nine locations of a LED display were compared with thresholds when focusing on the car ahead. A strong inverse relationship was found between time-to-collision (TTC) and eccentricity of the task to the normal line of sight, with TTC decreasing from 6 to 8 s at 0° eccentricity to 4 s at 90°. The results suggest that there are optimal locations, in terms of detecting the deceleration of a car ahead, for positioning attentionally demanding in-car devices, and that there are some differences in detection thresholds for similar eccentricities in the vertical and horizontal peripheries of the eye. Keywords: Driver distraction; Language: en