  Driver stress is a major cause of car accidents and death worldwide.
Furthermore, persistent stress is a health problem, contributing to
hypertension and other diseases of the cardiovascular system. Stress has a
measurable impact on heart and breathing rates and stress levels can be
inferred from such measurements. Galvanic skin response is a common test to
measure the perspiration caused by both physiological and psychological stress,
as well as extreme emotions. In this paper, galvanic skin response is used to
estimate the ground truth stress levels. A feature selection technique based on
the minimal redundancy-maximal relevance method is then applied to multiple
heart rate variability and breathing rate metrics to identify a novel and
optimal combination for use in detecting stress. The support vector machine
algorithm with a radial basis function kernel was used along with these
features to reliably predict stress. The proposed method has achieved a high
level of accuracy on the target dataset.
