An Emerging Framework to Inform Effective Design of Human-Machine Interfaces for Older Adults Using Connected Autonomous Vehicles

Abstract

Connected autonomous vehicles (CAVs) represent an exciting opportunity for wider access to mobility; especially for individuals unable to drive manual vehicles. Interaction with CAVs will be through human-machine interfaces (HMIs) providing journey-related and other information with some interactivity. These should be designed with potential users as part of a co-design process to maximize acceptance, engagement, and trust. This paper presents an emerging framework to inform the design of in-vehicle CAV HMIs with a focus on older adults (70-years+). These could be amongst early adopters of CAVs and tend to have the highest level of cognitive, sensory, and physical impairments. Whilst there are numerous principles on HMI design for older adults there are fewer on HMIs for AVs, and a need for research on CAV HMI design principles for older adults. Our emerging framework is novel and important for designers of CAV HMIs for older adults and other potential users.

Exploring the Usability of a Connected Autonomous Vehicle Human Machine Interface Designed for Older Adults

“…A recent review by [2] (see also [1]) synthetized best practice design principles to inform the development of CAV in-vehicle HMIs for use by older adults and individuals with sensory and/or physical impairments that would prevent them from driving or mean that driving ability is impaired. They organized these into five themed areas including general principles and ageing-related factors that could affect HMI accessibility and usability, and inform functionality and adaptability requirements.…”

“…The current paper presents findings from a simulator trial conducted to test the usability of a prototype CAV HMI designed for older adults and/or individuals with sensory and/or physical impairments: populations that will benefit enormously from the mobility afforded by CAVs. The HMI was developed to suit needs and requirements of this demographic based upon an extensive review of HMI and HCI principles focused on accessibility, usability and functionality [1,2], as well as studies with target users. Thirty-one 50-88 year-olds (M 67.52, three 50-59) participated in the study.…”

“…Both populations are likely to be early adopters of Level 4 and 5 CAVs due the significant and increased mobility options that they will offer. The key focus is on HMI usability and relationships with important factors such as situation awareness (SA), task load, attitudes towards computers, and, trust in technology and automation.A recent review by [2] (see also [1]) synthetized best practice design principles to inform the development of CAV in-vehicle HMIs for use by older adults and individuals with sensory and/or physical impairments that would prevent them from driving or mean that driving ability is impaired. They organized these into five themed areas including general principles and ageing-related factors that could affect HMI accessibility and usability, and inform functionality and adaptability requirements.…”

“…Key functionality examples include visual and auditory collision warnings, night vision enhancement and health and stress monitoring (e.g., [12], [13]). HMI adaptability refers to the ability to personalize features (e.g., text and image size/types) settings (e.g., option to display more or less information and have more or less steps to complete an action, and modes of interaction (see [1]).…”

“…Over and above the factors outlined above, [1,2] stressed the importance of the usability of CAV in-vehicle HMIs amongst older adults and/or individuals with sensory and/or physical impairments as a key determinant (as well as e.g., trust in CAVs) of their success, continued and future use (see also [14], [15], [11]). Morgan et al ( [1], p. 328) defined CAV HMI usability as '…aspects of the HMI including: learnability; efficiency; memorability: error handling; and satisfaction (linked with likelihood of continued use)'. Many of the recommendations are based on bodies of work focused on design principles for older adults ( [16], [17]) and can be divided into those that are important in terms of physical, sensory and cognitive factors.…”