Objective measures to assess workload for car driving

Understanding driver behavior is important for improving adaptability of driving assistant systems. The authors focused on workload, which was one of the most effective factors of driver behavior. The former study pointed that the workload for car driving consisted of ten factors that were revealed through the factor analysis in the survey. So, based on this finding, in order to assess quantity of the workload with physical measures that were obtained from driver behavior and the traffic environment, the relations of these were investigated. It was found that the operation times of the accelerator, brake and steering wheel, and index for complexity of driving scenes based on image processing could be used to quantify four of the workload factors.