Evaluation of Three In-Vehicle Interactions from Drivers' Driving Performance and Eye Movement behavior

Although in-vehicle interaction technologies offer assistances for drivers from multi-aspects, the distractions that may cause by these technologies would significantly challenge driving safety. This study examined the influences of three in-vehicle interactions on drivers' driving performance and eye movement behavior. The three in-vehicle interactions include phone pick-up (PPU), Bluetooth and audio $(\mathbf{BT}+\mathbf{AUD})$ and Bluetooth and head-up display $(\mathbf{BT}+\mathbf{HUD})$. A control group (i.e., None, in which no human-machine interaction was included while driving) was designed to highlight the influences of the examined interactions. Fourteen licensed drivers participated in the simulation experiments. Their age ranged from 20 to 30 years old $(\mathbf{Mean}\pm \mathbf{SD}=25.1\pm 3.8)$. They were required to complete the Location Based Service (LBS) tasks using the three interactions while driving. Both driving performance and eye movement data were collected for analysis. Results showed that, when using PPU or $\mathbf{BT}+\mathbf{HUD}$, the minimum throttle opening, the steering wheel angle (SWA) and the Shannon entropy (SE) of SWA were all greater than those values when using $\mathbf{BT}+\mathbf{AUD}$ or None. As for the SE of throttle opening and all the examined eye movement features (frequency and duration of fixation/saccade), the values when using $\mathbf{BT}+\mathbf{AUD}$ or $\mathbf{BT}+\mathbf{HUD}$ were higher than the values when using PPU or None. The presented results in this study provide evidences for car manufactures to design better $\mathbf{BT} +\mathbf{AUD}$ human-machine interaction systems as a priority strategy.