Search

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.

Two groups of six young and healthy subjects were used in this study to investigate the lateral path deviations when driving in a straight path with the eyes fixated on the road ahead, when driving while reading information inside of the automobile, and when driving with the eyes closed. Each group of subjects drove a typical large car and a typical small car at a fixed speed of 30 mph. An unused 2000 foot long and 75 foot wide, level, concrete airport runway was used to conduct the experiment. Each subject made three runs under each of the three conditions with the large car and with the small car (18 runs total). The lateral path deviations from the longitudinal centerline of the car to the centerline of the runway were measured every 15 feet for a distance of 705 feet. A device which dripped liquid dye was attached to the center of the rear bumper of the automobiles to indicate their paths. The results of this study show that the average lateral standard deviations for driving with the eyes fixated upon the road ahead were between 5.5″ and 11.3″. The difference in the lateral standard deviations for large and small automobiles was statistically not significant for distances between 100 and 500 feet from the starting point for the three conditions tested. The lateral standard deviation was smaller for reading text within the automobile than for driving with the eyes closed, and was statistically significant after an occlusion distance of 225 feet or an occlusion time of about 5 seconds. Using a constant of 0.041, the fundamental relationship between the lateral standard deviation, the speed, and the occlusion distance developed by Zwahlen and Balasubramanian (1974) fits the data for reading text inside of the automobile while driving fairly well. This constant is approximately one half of that which has been used for driving with the eyes closed (0.076) in this study. Based upon the results of this study, the development and introduction of sophisticated in-vehicle displays and/or touch panels should be halted and their safety aspects with regard to information aquisition, information processing, and driver control actions should be critically evaluated.

This paper reports on the preliminary results of a research effort being performed for the Department of Energy to investigate and evaluate methods of providing feedback to automobile drivers during vehicle operation which will help to promote fuel conservation. Popular so called “trip computers” and other fuel conservation devices are evaluated in the laboratory and on the highway. System concepts are developed to provide visual and auditory feedback to the operator utilizing appropriate locations for additional on-board displays. A variety of feedback devices are installed in a test vehicle for evaluation of user preference and the effectiveness of the device in promoting fuel conservation.

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.

The development of new visual displays and speach synthesizers leads to the on board presentation of additional information to the car driver. A series of laboratory and field experiments was carried out to compare visual, auditory, and partly combined presentation of binary and textual information. From the results recommendations for practical design can be given. Binary alarms which occur seldomly and with high priority have to be a dynamic signal, e. g. a blinking lamp optionally supported by an intermittent auditory signal. For textual information a voice warning system is recommended.

Older drivers present unique challenges to the display designer. Approximately 30 percent of all drivers in the U.S. are over 50 years of age. Visual impairment, e.g., presbyopia, begins after 40. After age 55, approximately 91 percent of the population use bifocals. Unfortunately, bifocals with significant add power create zones of decreased acuity in the critical instrument panel viewing distances of 500–800 mm. In this paper, the demands for vision in driving are related to the special visual disabilities associated with the older driver, such as increased sensitivity to glare, high contrast ratio blurring of electronic displays and increased time for target recognition. A computer legibility model is presented to relate the principal factors in design, namely character height and width, viewing distance, contrast ratio and background luminance with legibility impairment associated with various age groups. Implications of model predictions to display design are discussed.