Relationship between Predicted Stress and Measured Attentional Demand in a Simulated Driving Task

Abstract

The need exists for a method whereby a highway designer can determine, during the design stage, whether a highway design will demand so much of a driver's attention that he is left with insufficient time to look for and avoid accidents. Several methods exist for predicting how busy a subject will be under given circumstances. However, no direct comparisons between predicted stress and measured percent occupied have been attempted. In order to determine this relationship, various levels of difficulty of a tracking task and of a word-reading task were presented to 15 subjects. The stress for each difficulty level was predicted and attentional demand was measured directly. The relationship between predicted stress and percent occupied was found not to agree with the relationship commonly assumed in the literature on workload.