[Paper Review] Designing for Passengers' Information Needs on Fellow Travelers: A Comparison of Day and Night Rides in Shared Automated Vehicles

Lukas A. Flohr, Martina Schuß+3 more|arXiv (Cornell University)|Aug 4, 2023

Transportation and Mobility InnovationsEngineering3 citations

TL;DR

This study investigates how information about fellow passengers affects user experience, security perceptions, and trust in shared automated mobility-on-demand (SAMoD) systems during day and night rides. Using a simulated environment with 24 participants, it finds that providing personal details—especially photos—significantly improves perceived security and UX at night, but reduces satisfaction during the day, highlighting a key trade-off between security and privacy in system design.

ABSTRACT

Shared automated mobility-on-demand promises efficient, sustainable, and flexible transportation. Nevertheless, security concerns, resilience, and their mutual influence - especially at night - will likely be the most critical barriers to public adoption since passengers have to share rides with strangers without a human driver on board. As related work points out that information about fellow travelers might mitigate passengers' concerns, we designed two user interface variants to investigate the role of this information in an exploratory within-subjects user study (N = 24). Participants experienced four automated day and night rides with varying personal information about co-passengers in a simulated environment. The results of the mixed-method study indicate that having information about other passengers (e.g., photo, gender, and name) positively affects user experience at night. In contrast, it is less necessary during the day. Considering participants' simultaneously raised privacy demands poses a substantial challenge for resilient system design.

Motivation & Objective

• To understand how time of day (day vs. night) influences passengers’ security concerns and trust in shared automated mobility-on-demand (SAMoD) systems.
• To investigate whether providing information about fellow travelers (e.g., name, gender, photo) improves perceived security, trust, and user experience in SAMoD.
• To examine the tension between enhancing security through co-traveler information and the resulting privacy concerns among passengers.
• To inform the design of resilient, user-centered SAMoD interfaces that balance security, privacy, and user acceptance across different contextual conditions.

Proposed method

• Conducted a within-subjects user study with 24 participants in a high-fidelity immersive video-based driving simulator.
• Simulated four ride conditions: day and night rides with varying levels of co-passenger information (name, gender, photo, or no information).
• Used context-based prototyping to replicate real-world SAMoD experiences, including ride-sharing with strangers and lack of human drivers.
• Collected mixed-method data: quantitative surveys on trust, security, UX, and acceptance, and qualitative feedback on emotions and perceived risks.
• Analyzed data using mixed-methods analysis to identify patterns in user perceptions across time of day and information conditions.
• Focused on the in-vehicle interface as the primary modality for delivering co-passenger information, testing its impact on user perception and behavior.

Figure 1: Study participants experienced two day and two night rides in the immersive video-based automated vehicle simulator.

Experimental results

Research questions

• RQ1 How does the time of day (day vs. night) affect passengers’ perceived security and trust in shared automated mobility-on-demand (SAMoD) systems?
• RQ2 How does providing information about fellow travelers (e.g., name, gender, photo) influence passengers’ user experience, trust, and acceptance in SAMoD rides?
• RQ3 What is the interplay between perceived security and privacy concerns when personal information about co-passengers is displayed in automated vehicles?
• RQ4 How do gender and co-passenger composition influence passengers’ emotional responses and safety perceptions during shared rides, especially at night?

Key findings

• Providing personal information about co-passengers—especially photos—significantly improved perceived security and user experience during night rides.
• During the day, displaying co-passenger information, particularly photos, negatively affected user experience and system acceptance, suggesting context-dependent relevance.
• Participants reported higher anxiety and security concerns during night rides, especially when no information about co-passengers was provided.
• Both male and female participants preferred sharing rides with women over men at night, indicating gender-based safety preferences in low-visibility conditions.
• Despite valuing co-passenger information for security, participants expressed strong privacy concerns, revealing a key tension between security and privacy in system design.
• The study confirms that information about fellow travelers can enhance resilience in SAMoD systems but must be strategically timed and contextualized to avoid negative UX impacts.

Figure 2: Apart from time of day ("day" and "night"), study conditions varied in the amount of provided information on co-passengers: 1) without information, 2) with information. In the two rides with information, co-passengers’ age varied between "young" and "older".