This project consisted of three distinct empirical studies of the human and environmental factors that produce driving stress. The first investigation attempted to quantify individual differences in driver personality traits that make a driver more or less stress resistant. A psychometric methodology isolated four independent traits: time urgency, risk taking, hostility-anger, and cautiousness. The second investigation explored the relationship between age related cognitive deficits and driving performance among a group of elderly drivers. Age related declines in information processing ability may affect an elderly driver's ability to deal with either typical traffic situations, or with Intelligent Vehicle Highway Systems (IVHS) innovations, or both. The research indicated that a measure of attention switching ability, and a cognitive inference-reading comprehension test predict driving ability in elderly subjects. The third investigation consisted of a study of driver workload. The cardiovascular responses of drivers were measured under various real-world driving environments. The goal was to begin to provide a human factors perspective of surface street and freeway driving environments that can be used to shape the design and implementation of IVHS interventions. Phasic cardiovascular responses were found to detect workload changes that distinguish surface roads and freeways, amount of traffic congestion on freeways, and the impact of various "driving events" that occur during freeway driving. (Author/publisher)
Abstract