Performance decrement in vehicle driving.

Abstract : One hundred and eighty subjects were allocated to five groups on the basis of the number of hours the members of each group drove a truck on a fatigue course after an initial test, and prior to a re-test on a battery of nine driving tests. The fatigue periods were of 0, 1, 3, 7 or 9 hours duration. After determining the initial equivalency of the groups by an analysis of pretest results, post-fatigue test scores were correlated with hours of fatigue driving. All 15 test scores yielded part correlations significant at the 5% level of confidence or better. Correlations reached a maximum of r = .50. A decrement function was presented which showed progressive loss in performance through seven hours of driving. (Author)