Citation

Suhr VW. Highw. Res. Board bull. 1959; 212.

Copyright

(Copyright © 1959, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

During a 3-year period, 56 drivers were individually taken through an experimental 15-hr cycle. The first phase was to familiarize the subjects with the equipment and to minimize any practice effect that might be reflected. Because a pilot study showed that for variables of this type maximum performance was reached within the first 3 hrs of driving, the practice period was limited to 3 hrs behind the wheel. The second phase studied driving efficiency over a 6-hr period of simulated automobile driving. An attempt was made to determine the performance curve for variables amenable to continuous measurement. A series of psychological, physiological, psychometric, and psychophysical tests was administered both before and after the driving period to detect any changes that occurred in performance on certain factors relevant to safe driving. The effect of periodic tea pauses on the onset and extent of work decrement was noted. A personal evaluation from each participant was compared with driving performance and test results. The principal findings are as follows: (1) work decrement begins within the first 2 hrs of simulated automobile driving, (2) tea pause prolongs the onset and reduces the work decrement resulting from a prolonged period of simulated automobile driving, (3) the effect of a tea pause can be detected most readily by measurements made while the subject is actually performing, and (4) drivers either cannot or do not accurately evaluate their own level of driving efficiency.