Browsing by Subject "Older drivers"

Now showing 1 - 4 of 4
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    Empirical Bayes Identification of High Hazard Locations for Older Drivers
    (Minnesota Department of Transportation, 1994-10) Davis, Gary A.
    As part of an emphasis on improving road safety, the Minnesota Department of Transportation seeks to identify the locations where older drivers were over-represented in accident records. This research project reports on the use of three methods to help improve the accuracy of identifying locations where older drivers were at increased risk: a basic statistical model, the Empirical Bayes statistical method and a clustering method. Overall, the basic statistical model preformed the best. The clustering method and the Empirical Bayes method could both be usefully applied to the traditional task of high-hazard identification--that of automatically screening a large number of accident sites to identify potential candidates for improvement. This information can point the way to areas that may require a more detailed engineering analysis.
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    Factors influencing older drivers' left turn decisions
    (1993-10) Hancock, Peter A.; Caird, J.K.
    Perhaps no frequent driving maneuver is more hazardous than the left turn. Existing statistical analyses indicate that the older drivers are over represented in the left turn configuration. It is not surprising that the left-turn proves such a hazardous configuration since the turning driver has minimal, obscured, and conflicting information upon which to base their turn decisions. In addition, understanding the problems of the left-turn presents a number of information and task decomposition challenges. For example, given a driver's expected vehicle response, prediction of other vehicles future positions relative to the driver's own position must be visually interpreted from available motion-in-depth information. Some have likened the task of the turning driver to one of coincident timing, where turn initiation and completion must be synchronized with acceptable gaps in on-coming traffic (2). Acceptability is predicated on each individual drivers perception of this traffic in terms of physical characteristics (3, 4). Objectively, vehicles can vary in terms of their relative approach velocities, the changing gap difference between themselves and the vehicle they follow, and their configuration in terms of size, shape, and color. If drivers use these physical variables singly, changes in turn strategies would logically be consistent with such physical parameters. If, however, drivers base their decisions on higher-order information sources like rate-of-expansion of the vehicle frontal surface (time-to-arrival), the pattern of results would not be consistent with manipulations of these physical properties. Previously, this proposition was tested for a college-age population in the University of Minnesota's fixed-based automobile simulator (5). This group of drivers, with a mean age of 24.2, initiated left-turns, not on the basis of any physical metric, but through inference on time-to-arrival information. The present experiment examines the same driving maneuver in older drivers. We hypothesized that the turn strategies employed by older drivers would be, in part, mediated by these same higher-order information sources, but that the scaling of that information relative to their own self-perceived limitations would render them more conservative in a manner consistent with traditional performance speed assessment metrics such as visual search time and reaction time.
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    A Simulator-Based Evaluation of Smart Infrastructure Concepts for Intersection Decision Support for Rural Thru-STOP Intersections
    (Minnesota Department of Transportation, 2007-08) Creaser, Janet; Rakauskas, Mick; Ward, Nic; Laberge, Jason
    This report describes the human factors basis for an intersection decision support (IDS) system intended to improve the safety of rural intersections in Minnesota's Interregional Corridors (IRCs). The purpose of the human factors effort is to understand the task of rural intersection negotiation, identify high-risk user groups, describe the human factors that contribute to intersection accidents, and determine what conceptual types of information to present in the IDS display to improve driver performance and safety. Consistent with the original infrastructure consortium proposal, this report emphasizes gaps, older drivers, and rural thru-STOP intersections (Donath & Shankwitz, 2001). This is because older drivers have a high accident risk at rural thru-STOP intersections and problems with gap detection, perception, and acceptance are contributing factors. A task analysis of rural thru-STOP negotiation was used to define the informational requirements for an IDS system for assisting with gap detection, perception and judgment. An abstraction hierarchy defined the operator (driver) constraints relevant to an infrastructure-based IDS system. Four design concepts were constructed and tested in a driving simulator with older (55+) and younger (20-40) drivers in day and night driving conditions. Two designs resulted in the largest mean gap acceptance across groups when compared to baseline. The two design concepts also were most favored by the majority of participants.
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    The Use of Driving Simulation for the Assessment, Training and Testing of Older Drivers
    (1990-01) Hancock, Peter A.; Caird, J. K.; White, H. G.
    With the lowering of the birth rate over the last decade and a half, and the increased life expectancy associated with improving health care, the United States is undergoing a radical aging of its populace. This change in demographic structure is embedded in a society experiencing clear and rapid advances in its technological capability (Abend & Chen, 1985; U.S. Congress, 1985; Tobias, 1987). One ramification of these combined developments is that expectations of activity and lifestyle change rapidly across successive cohorts. Typically, each sequential cohort expects to retain access to progressively wider ranges of activity which have become characteristic of their respective lifestyles. Contemporary and future cohorts will expect continued access to the privilege of autonomous mobility, typically through the use of the automobile (Wachs, 1988; Waller, 1972). This aspiration generates a conflict between two powerful and somewhat antagonistic societal forces. On one side is the traditional and expected freedom that emanates from owning and operating a personal automobile. On the other is the potential and actual safety hazards associated with the actions of an aging central nervous system having to cope with progressively more complex and demanding driving environments (Federal Highway Administration, 1986). The potential resolution of this conflict lies in the use of a systems approach as a framework to apply Human Factors principles to improve the driving environment, the vehicle, and facilitate the capabilities of the driver. Unfortunately, there is little research available that is specifically directed at the Human Factors problems faced by aging drivers with regard to design of automobiles, roadways, and roadway communication symbols (Forbes, 1985; Staplin, Breton, Haimo, Farber, & Byrnes, 1986; Yanik, 1989). Consequently, there is a fundamental need for research efforts in this area. It is one facet of this systems-based strategy (Doebelin, 1980), namely the use of simulation in training, testing, and evaluating the older driver, that is the focus of the present report.