When Do Users Prefer Voice-Controlled Systems in Vehicles? A Survey of Chinese Drivers
BY Dengbo He and Chunxi Huang
In-vehicle information systems (IVIS) have become increasingly prevalent in the smart cockpit of modern vehicles. The IVIS can allow drivers to get access to various types of in-vehicle functions, including controlling entertainment systems (e.g., selecting songs), making communication (e.g., making phone calls), changing in-vehicle settings (e.g., setting the temperature in the vehicle) and planning a trip (e.g., setting navigation). Traditionally, the IVIS interactions mainly relied on manual interactions (or MIs), which include physically haptic buttons and touch-based interactions. However, due to its physical essence and limited cockpit space, physically haptic buttons could only support very limited functions and can hardly be updated once a vehicle is sold, which is less favored by users compared to touch-based interactions in recent years. Though touch-based interactions offer great flexibility in in-vehicle functions, touch-based interactions can be visually distracting in vehicles and raise safety concerns. To overcome the limitations of physical buttons and touch-based interactions, in recent years, more and more vehicles have been equipped with vehicle control systems (VCSs), which influence less driving and visual performance and thus can be potentially safer compared to touch-based interactions. However, though the advances in machine learning and natural language processing have made VCS increasingly accurate and reliable, the safety benefits of the VCS are still controversial. It is also alerting that drivers feel safer when using VCS compared to manual text entry, which may potentially lead to increased engagement with VCS-based NDRTs in vehicles. This raises a concern about whether drivers can modulate their engagement with in-vehicle tasks offered in smart cockpits.
Therefore, as a preliminary effort, this study aims to understand drivers’ choices in using VCS for six common IVIS tasks under different scenarios through a survey study. The six common tasks during driving included: 1) adjusting the temperature in the vehicle to a specific temperature; (2) selecting a specific song in the favorite music list to play; (3) making a phone call to a specific person in the contact list; (4) compiling and sending a text message; (5) navigating to a specific destination; (6) opening or closing the window; and the scenarios were defined by passenger presence (driving alone or with colleagues), roadway type (urban vs. highway) and traffic density (low vs high). A questionnaire was designed and valid data from 168 Chinese drivers were collected.
We find that drivers’ choice of the interaction modality is associated with the driving scenarios. Specifically, drivers prefer VCS when they are driving alone, driving on highways, and driving in an environment with high traffic complexity. Further, drivers have different preferences of interaction modalities for different tasks: when tasks are more distracting and more time-demanding, drivers prefer VCS over manual interactions. Moreover, the preference for interaction modalities can also be affected by the characteristics of drivers: those with lower driving frequencies and higher VCS familiarity and those who perceive VCS as easier to use tend to choose VCS as an interaction modality for IVIS tasks. The findings from this study provide insights for understanding drivers’ choice of interaction modalities under different scenarios, which could guide the design of customized or adaptable in-vehicle interactions in smart cockpits from driving safety and user satisfaction perspectives of view.
Article Details
When Do Users Prefer Voice Control Systems in Vehicles? A Survey of Chinese Drivers
Chunxi Huang, Song Yan, Weiyin Xie, Dengbo He
First Published April 25, 2024 Research article
DOI: 10.1177/03611981241240771
Transportation Research Record: Journal of the Transportation Research Board
About the Authors
