Abstract. Prior researchers indicate that mental load is one of the most important contributors to a traffic accident. The aim of the paper is to investigate the impact and the correlation of road condition and driving experience on driver's mental workload. The driving test consists of 3 road complicity situation (urban road, highway, rural road) with 26 drivers with average 21 years old in different experience level (average 4.08 years' experience). NASA TLX questioner is used as subjective driver's mental load measurement with three dimensions relate to the demands imposed on the subject (Mental, Physical and Temporal Demands) and three to the interaction of a subject with the task (Effort, Frustration, and Performance). There are 3 cameras placed on the left side, right side and front car to identify the road condition. According to experiment, it was found that drivers felt that frustration level, business, and mental-demand factors dominate the impact on high-level workload (96.15%). Highway road conditions provide an average overall workload score of 62 (OWS) which was better compared to city road (OWS = 69) and rural road (OWS = 66). Based on street complexity, it is necessary to improve road conditions that resemble highway road by reducing potential hazard.
Keywords: Mental driving workload, NASA TLX, Overall workload score (OWS)
I IntroductionDriving is main human activity which is conducted to support daily activities and mobility in the shortest time possible. This initiated large government investment in providing safe and convenient transportation system. The driving complexity causes road accidents, not only due to physical factors such as cars and road conditions but also due to human factors themselves such as human error and excessive stress levels. Fastenmeir and Gstalter [1] research define that the complexity of driving depends on elements such as road design (highway, rural road, city road), road layout (straight, curved, inclined, junction) and traffic flow (high density). The study of the situation and the pattern of the relationship between drivers with cars and driving environments in order to reduce or avoid possible risk. The driver's ability to meet driving needs becomes an important capital in realizing safety driving [2]. The ability to adapt quickly, such as reducing speed, changing the direction of the vehicle is very much dependent on driving experience and mental condition (load) of the driver.Schlegel [3] defines driving workload as the total amount of resources or driver's ability to achieve a driving task. Further driving workload reflects the driving need to achieve performance tasks that depend on individual drivers and skills. Driving workload depends on the task (demand, complexity, and difficulties), drivers (age, fatigue, abilities, experience, etc.) and environment (dynamic/changing, familiar, etc.). Total driving workload consists of every aspect relating to driving task and nondriving task [4]. Driving tasks consist of street monitors making lateral/longitudinal ac...