HMI for Rideshares for People with Visual Impairments
A human-centered, multimodal HMI (audio + visual) that bridges the accessibility gap in autonomous ridesharing.
Accessibility focused
Team of 4
3.5 months
Project Overview
Imagine you were injured and didn't have a partner/friend to drive you where you needed to go. How would your life be impacted? 25 million Americans alone experience transportation insufficiency stemming from cognitive, sensory, and/motor impairments. Without reliable, usable transportation, these individuals are further left behind and isolated from society.
Autonomous vehicles promise independent mobility, but most HMIs are vision-first. Blind and low-vision riders face barriers during identity verification, trip confirmation, en-route updates, unexpected events, and safe exit. We set out to design a multimodal interface that restores confidence, safety, and autonomy.
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Design Challenge
How might we design a human-machine interface (HMI) that promotes independent transportation for visually impaired individuals by integrating their other senses?
Project Details
Role
UX Researcher & Designer
Timeline
September - December 2024
Responsibilities
Research, wireframing, analysis, usability testing, VADER sentiment analysis​
Publication​https://doi.org/10.1177/10711813251357895
Tools
Matlab
Figma
Cambridge Disability Simulator
Research & Discovery
We broke down the ridesharing process with impairment needs included. From start to finish, the ridesharing process was broken into six tasks and ran a between-subjects usability study to measure trust, navigation accuracy, and satisfaction across tasks. The six tasks were: identity verification, trip confirmation, driving updates, unexpected events, destination arrival, and exit interaction.
Identification verification
Speak 4-digit ride code; confirm rider-vehicle pairing.
Trip Confirmation
Destination read back and verbal confirm or address correction.
Driving Updates
Proactive status: intersections, signals, ETA changes.
Unexpected Events
Special mode explains hazards and evasive actions.
Destination Arrival
3-minute pre-arrival alert; curbside context.
Exit Interaction
Guided, safe, step-by-step disembarkment.
Design Principles & Prototype
Attention Management
Salience, urgency mapping, and interruption handling.
Perception Optimization
Low access cost, redundancy, progressive disclosure.
Memory Supports
Predictive cues, consistent language, knowledge-in-the-world.
Prototype Stack
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Rear-seat mounted display for route status & environmental descriptions
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External speaker with natural voice (Maple) for synchronized audio prompts
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High-contrast hardware buttons (#F4B300, #B87AFF) for tactile control
Experiment Design
Between-subject design (N = 24) with 3 conditions:
1. Non-Visually Impaired (NVI): Multimodal interface​
2. Visually Impaired (VI): Multimodal interface
3. Visually Impaired (VIX): Visual-only (no audio)
Measures
Trust, satisfaction, navigation accuracy (Likert; Kruskal–Wallis + post‑hoc).
Interviews & Literature Review
Preference for audio‑visual redundancy; clarity & directionality themes. 27 articles reviewed.
Simulation
Cambridge Disability Simulator at 20/200 acuity blur for standardization.
Key Findings
Trust & Satisfaction
VI with audio ≈ NVI; visual‑only significantly worse
(p < .05).
Correct Rideshare
Audio restored confidence in vehicle identification.
Navigation
Proactive narration improved route understanding & comfort.
Participant's thoughts
"Without audio prompts, I couldn’t tell if the car was moving or stopping."
— Participant VIX‑03
Prototypes & Mockups
Unimpaired vs impaired view of screen
Wizard-of-Oz simulation for usability testing
Mockup of multimodal system if fully autonomous vehicles existed.
Results & Next Steps
Next Steps
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Field trials with blind and low-vision riders in real AVs across varied road conditions.
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Introduce haptics (seat vibration, localized speakers) for tri‑modal redundancy.
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Personalization preferences: verbosity, pace, tone, and cue frequency.
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Safety sandbox studies for edge cases: reroutes, obstructions, emergency stops.
Laura Weisz
UX Researcher & Designer passionate about accessible. engaging, user-friendly digital experiences that make a meaningful impact on people's lives.
Navigation
2025 Laura Weisz
Contact Info
Email: laurakweisz@gmail.com
Location: USA