Date of Award

Spring 1971

Document Type

Thesis - Restricted

Degree Name

Master of Science (MS)


Civil Engineering

First Advisor

Simba, Kumares C.

Second Advisor

Bauer, Kurt

Third Advisor

Lawrence, Willard


Statement of the Problem During the process of merging, a ramp driver is required to very quickly assess a dynamic and highly complex traffic situation occurring in the freeway lane into which he must merge. Vision is the key biomechanism which he has at his disposal to transmit external stimuli, by perception, to the intellection- analysis center of the brain for decision and transmission of action commands to the extremities which mechanically control the automobile. The visual part-task is hindered by the physical limitations of gross movements of the head due to the muscular structure of the human body. Gross horizontal eye movement, or the angular movement of the visual centerline of regard is consequently constrained. Both the horizontal and vertical visual part-tasks are further restrained due to freeway and ramp roadway geometry and vehicular obstructions. Left-hand entrance ramps apparently impose more external constraints on the visual part-task-than do right-hand entrance ramps . No mathematical data has, as yet, substantiated whether or not these constraints seriously inhibit the driver's ability to merge due to significantly restricted horizontal and vertical visual scans. The computer model developed for this study mathematically described visual constraints due to the elements external to the driver physiological system. Statement of Procedure The dynamic traffic situation was discretized and mathematically presented to the computer. By internally performing consecutive process iterations, after successive incremental updates, man readable mathematical data representing the occurrences during advancement of time were output from the computer. Results The output was statistically analyzed for both the experimental (left-hand merge) and the control (right - hand merge ) situations. The results were statistically compared, and it was concluded that, in a majority of cases, left hand ramps are inferior to right hand ramps because of visual obstructions caused by their geometric layout.



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