[Paper Review] Trust in Shared Automated Vehicles: Study on Two Mobility Platforms

Shashank Mehrotra, Jacob G. Hunter+7 more|arXiv (Cornell University)|Mar 17, 2023

Transportation and Mobility Innovations4 citations

TL;DR

This study investigates trust dynamics in shared automated vehicles (SAVs) using a dual-mobility simulator with 48 participants who experienced both car and sidewalk automated mobilities. Participants showed significantly higher trust in the second mobility they used, especially when transitioning from car to sidewalk, indicating that trust transfer and building are influenced by mobility sequence and perceived reliability.

ABSTRACT

The ever-increasing adoption of shared transportation modalities across the United States has the potential to fundamentally change the preferences and usage of different mobilities. It also raises several challenges with respect to the design and development of automated mobilities that can enable a large population to take advantage of this emergent technology. One such challenge is the lack of understanding of how trust in one automated mobility may impact trust in another. Without this understanding, it is difficult for researchers to determine whether future mobility solutions will have acceptance within different population groups. This study focuses on identifying the differences in trust across different mobility and how trust evolves across their use for participants who preferred an aggressive driving style. A dual mobility simulator study was designed in which 48 participants experienced two different automated mobilities (car and sidewalk). The results found that participants showed increasing levels of trust when they transitioned from the car to the sidewalk mobility. In comparison, participants showed decreasing levels of trust when they transitioned from the sidewalk to the car mobility. The findings from the study help inform and identify how people can develop trust in future mobility platforms and could inform the design of interventions that may help improve the trust and acceptance of future mobility.

Motivation & Objective

• To understand how trust in one automated mobility platform influences trust in another, particularly across different mobility types.
• To examine the evolution of trust in shared automated vehicles (SAVs) when users experience multiple mobility platforms.
• To investigate whether driving style preferences—specifically aggressive driving—impact trust formation in automated systems.
• To assess how reliability and exposure sequence affect trust dimensions such as competence, predictability, and faith in automation.
• To inform future design of trust-building interventions in automated mobility platforms

Proposed method

• Conducted a dual-mobility simulator study with 48 participants experiencing both car and sidewalk automated mobilities in randomized order.
• Maintained consistent automation reliability across both platforms to isolate the effect of mobility type and sequence on trust.
• Used a driving style preference survey to tailor automation behavior to participants’ preferred aggressive driving profiles.
• Collected quantitative trust data via standardized trust surveys before and after each mobility experience.
• Complemented quantitative data with semi-structured qualitative interviews to explore participant perceptions and reasoning.
• Analyzed trust dimension changes (reliability, competence, predictability) across mobility transitions, focusing on sequence effects.

Experimental results

Research questions

• RQ1 How does the sequence of exposure to different automated mobility platforms (car vs. sidewalk) affect users’ trust in those systems?
• RQ2 To what extent does trust in one automated mobility transfer or evolve when users switch to a different mobility type?
• RQ3 How do aggressive driving preferences influence trust formation in automated shared mobility platforms?
• RQ4 What role does perceived reliability and predictability play in the development of trust across different automated mobilities?
• RQ5 What qualitative factors contribute to differences in trust, particularly regarding safety perceptions and environmental context?

Key findings

• Participants who used the car mobility first reported higher trust in the sidewalk mobility, indicating a positive transfer of trust across platforms.
• Participants who used the sidewalk mobility first reported lower trust in the car mobility, suggesting that initial exposure shapes subsequent trust expectations.
• The reliability/competence dimension of trust increased significantly when participants transitioned from car to sidewalk mobility, despite the sidewalk's lack of physical enclosure.
• Qualitative feedback indicated that participants trusted the car more due to predictable road rules and physical protection, while sidewalk mobility was perceived as less safe due to pedestrian unpredictability.
• The tutorial significantly improved baseline trust in sidewalk mobility, suggesting that education and exposure can mitigate initial distrust.
• Trust was not initially dependent on demographic factors, but future work will explore correlations with demographics, takeover intent, and physiological states.