Research on the effect of control size and location of human-machine interface display on drivers’ multi-resource demands

Abstract

Interaction by touching a human–machine interaction (HMI) display has gradually evolved into the mainstream mode of human-vehicle interaction. Limiting the level of driver distraction caused by HMIs is an important concern. To explore the different positions and sizes of controls based on the multi-resource demands of the driver, a driving simulator experiment was conducted. The goal was to collect behavioral and subjective workload data from drivers performing secondary tasks under various conditions. Overall, the resources required by the driver to perform secondary tasks were relatively low on the left side of the HMI display and relatively high on the right side. Specifically, the lower-left position of the HMI display required the least resources, whereas the upper-right position required the most. Consequently, the results indicate that the resource demands of the secondary task on the driver decrease as the size of the controls increases. Most drivers preferred a “compromise” control size (18 mm). To reduce the resource demand, the control size of the HMI display should be set to at least 14 mm. This study has high industrial application value, and the results provide guidance for designing in-vehicle HMI displays with improved safety and usability.