A Validation Study on a Subjective Driving Workload Prediction Tool

A variety of methods used to measure a driver´s workload do not include information such as the driver´s characteristics and attitudes. A subjective driving workload prediction tool (DWPT) was developed to overcome this limitation. The purpose of this study is to validate the DWPT, which is composed of three subfactors: the situational inadaptability, the risk-taking personality, and the interpersonal inadaptability. For this reason, we conducted the driving simulator experiment to gather the drivers´ driving behaviors. The driving path scenario included various driving tasks. Thirty male drivers participated in this study. The analysis results showed that a driver´s predicted score of subjective driving workload had a positive or a negative relation to their workload-related driving behaviors such as the operation of the indicator/steering/gas pedal and gaze behaviors. In particular, two subfactors, i.e, the risk-taking personality and the interpersonal inadaptability, were more closely related to their driving behaviors than the total predicted subjective driving workload and the situational inadaptability subfactor. These results suggest that a DWPT could be used to predict the drivers´ subjective driving workload instead of measuring the driving performance or self-reporting questionnaire. In addition, this would be expected to be available on the area of the Advanced Driver Assistance System and drivers´ safety industry.