Citation

Biondi FN, Getty D, Cooper JM, Strayer DL. Transp. Res. F Traffic Psychol. Behav. 2019; 62: 520-528.

Copyright

(Copyright © 2019, Elsevier Publishing)

DOI

10.1016/j.trf.2019.02.006

PMID

unavailable

Abstract

Given the promise for auditory-vocal systems to be less distracting and safer to use than their visual-manual counterparts, automotive manufacturers are introducing an increasing number of voice assistant-like interfaces in vehicles. However, recent studies suggest using auditory-vocal systems can be mentally taxing for drivers, and require long interaction times. Low accuracy and menu complexity are believed to negatively affect the usability of the system, but a systematic analysis of the role of different design components on driver workload and user experience within a real-world setting is missing. This study investigates the role of voice system design components in determining levels of driver workload with participants driving twelve on-road vehicles and interacting with on-board infotainment systems. Menu depth, delay times and system accuracy are recorded for twelve different auditory-vocal systems, and one aggregate score is assigned to each system. Total delay time and menu depth were found to be significant predictors of task duration time and mental workload. Longer delay times also had a direct effect on lower usability ratings, measured by the System Usability Scale and sentiment analysis. Delay times recorded on seven additional vehicles were used to validate the regression model for task duration. This study provides findings of primary importance for researchers and automotive manufacturers to be used in the assessment and development of in-vehicle auditory-vocal systems.

Language: en

Keywords

Auditory-vocal systems; Distraction; Driving; Human-machine interfaces; Usability; Workload