Browsing by Author "Williams, Gayna"

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    Human Factors Evaluation of the Delco RDS Radio Receiver and the RDS Architecture
    (1994-08) Burrus, Max E.; Johnson, Sara M.; Williams, Gayna; Stackhouse, Stirling
    This report presents the results of a one year comprehensive human factors analysis on the prototype Delco RDS device supplied by the Minnesota Department of Transportation. RDS devices provide a means of transmitting traffic information to motorist using the existing Traffic Management Center's resources. This study examined the devices and the means of transmitting information using ergonomic and human factors principles. This study expanded upon the functions of these devices and their ability to transmit information, as well as their integration within the automobile. The study was completed by examining the data entry tasks required to transmit messages and the TMC's operations as pertaining to messages and delivery to the end-users. Five tasks were completed with the following findings: Ergonomically, the prototype device requires further refinement to provide a user friendly interface. Linkage analysis and flow charting extracted areas where operations of the device was impeded by design. Simulation and on-road study elicited difficulty in operating the device while maintaining driving proficiency. Highly significant deviations were found between normal driving behavior and driving performance when simultaneously operating the device. This suggests an increase in attentional demand which is placed on the driver operating the device when they should be focused on the task of driving. Finally, assessment of data entry personnel and the TMC operations found several areas for improvement in the CrusaderTM message assembly program interface and message content. Recommendations are provided following each task.
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    Lighted Guidance Devices: Intelligent Work Zone Traffic Control
    (Minnesota Department of Transportation, 1995-06) Vercruyssen, Max; Williams, Gayna; Wade, Michael G.
    Annually, thousands of highway workers risk serious injury and death from drivers who enter work zones too fast or accelerate after entering the zone and then, because of their excess speed relative to the environmental limitations, have insufficient time to avoid accidents in the zone. Slow-moving vehicles are a problem in reducing traffic flow. This research investigated the effectiveness of a system of pulsing lights, that gave the illusion of movement (Phi phenomenon), in causing drivers to unknowingly synchronize their vehicle speed with the light pulses. Forty drivers participated: 20 young (10 female, 10 male; 21-42 years) and 20 older adults (10 female, 10 male; 55-87 years). Each participant made 15 passes through the work zone: a control pass with stationary white lights, two control passes with no lights, and 12 passes of test conditions -- 2 colors (red & green) x 3 apparent pulse speeds (-80, 0, & +80 mph) x 2 zone entry speeds (40 & 70 mph). Age, sex, and zone entry speed differences were found, but overall, (1) backward moving lights (-80 mph) caused drivers to reduce their vehicle speed, (2) forward moving lights (+80 mph) caused drivers to increase their vehicle speed, (3) stationary light and control lights had little or no effect, and (4) green produced stronger effects than red. Backward moving lights caused the greatest slowing in the young while forward moving lights caused the greatest acceleration in the old males and young females.