Theses and Dissertations (VTTI)
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Browsing Theses and Dissertations (VTTI) by Author "Dingus, Thomas A."
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- Attentional demand evaluation for an automobile moving-map navigation systemDingus, Thomas A. (Virginia Tech, 1987)A study was undertaken to test and evaluate the human factors design aspects of an automobile moving-map navigation system. The primary objective of the study was to assess the driver attentional demand required by the navigation system during vehicle operation. A secondary objective of the study was to assess design specifics and determine whether or not the design was optimal in terms of efficiency of use in an automotive environment. Thirty-two driver-subjects drove a specially instrumented 1985 Cadillac Sedan de Ville on public roadways for this research. A cross-section of driver-subjects (both genders, ages 18 to 73, and driving experience from 2,000 to 40,000 miles per year) participated, and a cross·section of roadway types (residential, two-lane state route, and limited·access four-lane) and traffic conditions (light and moderate) were used as part of this research. The driver-subjects were asked to perform a variety of tasks while operating the research vehicle. These tasks included navigation tasks normally performed while using the navigation system, as well as a wide variety of conventional automotive tasks (e.g., tuning the radio or reading the speedometer) normally performed during vehicle operation. The purpose of asking the driver-subjects to perform a variety of conventional automotive tasks was so that direct comparisons in attentional demand could be made between tasks performed daily in an automotive environment and the navigation tasks. Twenty-one performance and behavioral measures were collected and analyzed for this research. These measures included eye—scanning and dwell-time measures, task-completion-time measures, and a variety of measures indicating driver performance and behavior. The data analyses for these measures focused on two major goals. First, the analyses determined which tasks (both navigator and conventional) required the highest attentional demand. Second, the analyses were used to determine groups of tasks which, for all practical purposes, required equivalent attentional demand. The results of the analyses indicated that the navigation system is a relatively effective device, useful for its intended purpose. The results also indicated that a number of design improvements are required, however, to optimize the safety and efficiency of the device. An iterative process of design improvement and further research into the effects of improved design on required attentional demand is therefore recommended.
- Development of models for detection of automobile driver impairmentDingus, Thomas A. (Virginia Tech, 1985-08-05)Two of the leading causes of automobile accidents are driver impairment due to alcohol and drowsiness. Apparently, a relatively large percentage of these accidents occur because drivers are unaware of the degree to which they are impaired due to these sources. The purpose of this research was to develop models which could detect driver impairment due to alcohol, drowsiness, or the combination of alcohol and drowsiness, and which could be practically implemented in an automobile. Such detection models, if successfully implemented in conjunction with a system to warn an impaired driver of his or her condition, could potentially save hundreds of lives each year. Six driver-subjects operated a computer controlled driving simulator during each of four conditions. The four conditions consisted of a control condition, an alcohol condition, a sleep-deprived condition, and a combination alcohol and sleep-deprived condition. Moderate levels of alcohol and sleep deprivation were used for this study. Nineteen performance and behavioral measures were collected during this study. Each measure was evaluated singly and in combination with other measures to determine potential value for detection of driver impairment. Detection models were then formulated using the most promising detection measures. The results indicated that a useful on-board drowsiness impairment detection device is possible and practical for highway driving. This device would also, in all likelihood, provide useful detection information regardless of whether low to moderate amounts of alcohol were present in a drowsy driver. The results also showed that on-board alcohol impairment detection may be possible at moderate to high BAC.
- Effects of In-Vehicle Information Systems (IVIS) Tasks on the Information Processing Demands of a Commercial Vehicle Operations (CVO) DriverBlanco, Myra (Virginia Tech, 1999-12-10)This study was performed with two main goals in mind. The first goal was to understand and predict "red-lines" and "yellow-lines" in terms of what the CVO driver can process without hindering the primary task of driving. The second goal was to collect conventional secondary task data for CVO driving performance. An on-the-road experiment was performed with the help of 12 truck drivers. Type of task, presentation format, information density, and age were the independent variables used in the experiment. The 22 dependent measures collected were grouped into the following categories: eye glance measures, longitudinal driving performance, lateral driving performance, secondary task performance, and subjective assessment. The findings of this study strongly suggest that paragraphs should not be used under any circumstance to present information to the driver while the vehicle is in motion. On the other hand, the Graphics with Icons represent the most appropriate format in which driving instructions and information should be presented for IVIS/CVO tasks. In order to avoid a high visual attention demand to the driver due to a secondary task, only simple search tasks with the most important information shall be presented. Although the suggested format, type of task, and information density represent a higher visual attention demand than a conventional secondary task, these characteristics seem to bind a task with a moderate attentional demand. Other combinations of format, type of task, and information density will cause an increase in the driver's attentional demand that will consequently deteriorate their driving performance causing unsafe driving situations.
- The Impact of Local/Short Haul Operations on Driver FatigueHanowski, Richard J. (Virginia Tech, 2000-05-23)Massie, Blower, and Campbell (1997) indicate that trucks that operate less than 50 miles from the vehicle's home base comprise 58% of the trucking industry. However, despite being the largest segment, research involving local/short haul (L/SH) operations has been scant. In fact, little is known about the general safety issues in L/SH operations. As a precursor to the present research, Hanowski, Wierwille, Gellatly, Early, and Dingus (1998) conducted a series of focus groups in which L/SH drivers provided their perspective on safety issues, including fatigue, in their industry. As a follow-up to the Hanowski et al. work, the effort presented here consisted of an on-road field study where L/SH trucks were instrumented with data collection equipment. Two L/SH trucking companies and 42 L/SH drivers participated in this research. To the author's knowledge, this is the first in-situ data collection effort of its kind with L/SH drivers. The analyses focused on determining if fatigue is an issue in L/SH operations. Of primary interest were critical incidents (near-crashes) where drivers were judged to be at fault. The results of the analyses indicated that fatigue was present immediately prior to driver involvement in at-fault critical incidents. Though it is difficult to determine why fatigue was present, the results seem to indicate that much of the fatigue that the drivers' experienced was brought with them to the job, rather than being caused by the job. There are four basic outputs of the Phase II research: (1) a description of the L/SH drivers who participated, (2) a description of critical incidents, (3) a determination if fatigue is an issue in L/SH trucking, and (4) the validation of the fatigue factors cited in Hanowski et al. (1998) using a proposed fatigue model. These four outputs culminate in a set of pragmatic guidelines to address fatigue and other safety issues in L/SH operations. Five guidelines are proposed that are directed at: (1) driver education with regard to on-the-job drowsiness/inattention, (2) driver education with regard to sleep hygiene, (3) driver training, particularly for novice L/SH truck drivers, (4) driver screening, and (5) public monitoring of L/SH driver performance.