The aim of present study was to investigate the effect of a newly developed steering unit with enhanced self-alignment and deadband on mental workload (MW) during heavy vehicle operation. Fourteen participants performed two tasks consisting of a lane keeping and a double lane shift with two tractors equipped with 1) a conventional and 2) an enhanced steering system. Physiological measurements, i.e., electromyography, electrodermal activity and heart rate were recorded during the tasks. Furthermore, performance measurements and subjective perception of MW were collected. Present study demonstrated that participants perceived the enhanced steering system requiring less mental demands to operate. Participants improved their performance during the lane keeping task and tended to improve in the double lane shift task with the enhanced system. Physiological measurements did not reveal differences between the steering systems. This study highlighted the dissociation of subjective indices of mental workload from physiological indices in driving of heavy vehicles.

本研究的目的是研究重型车辆操作过程中新开发的具有自动对准和死区增强功能的转向装置对精神工作量（MW）的影响。14名参与者用两台配备1）常规拖拉机和2）增强转向系统的拖拉机执行了包括保持车道和双车道换档在内的两项任务。在任务期间记录生理测量值，即肌电图，皮肤电活动和心率。此外，收集了性能测量和对MW的主观感知。当前的研究表明，参与者意识到增强的转向系统需要更少的精神要求来进行操作。参加者在保持车道的过程中提高了他们的表现，并通过增强的系统在双车道换挡任务中得到了改善。生理测量结果并未显示出转向系统之间的差异。这项研究强调了重型车辆驾驶中精神工作量的主观指标与生理指标的分离。