Interactive Wayfinding for Visually Impaired Users in Subways

Aura Ganz, James Schafer, Yang TaoCollaborators:

MCB: Carole Wilson, Charlene Sanderson, Meg RobertsonTravel Trainer: Larry HaileMBTA System-Wide Accessibility Dept. - Laura BrelsfordCONTACT: ganz@ecs.umass.edu

Funded by:

New Freedom GrantMBTA

Outline

• Introduction• PERCEPT in MBTA Subway• Demonstration• Trials• Conclusion

Introduction

• Enables blind users to independently navigate in unfamiliar indoor environments

• Percept is an orientation aid used in conjunction with mobility aids

• Co-Designed with Certified Orientation and Mobility Specialists (COMS) from Massachusetts Commission for the Blind

• Successful trials conducted at UMASS and MBTA subway station with over 40 blind and visually impaired human subjects

• Featured several times in:

• Latest Article

(Universal) Design Principles

– Cost efficient:• For user: Smartphone based• For facility: Low cost – passive tag deployment, automated

navigation instruction generation

– Simple and Intuitive Use: System uses Smartphone accessibility features (“Talkback”)

– Perceptible Information: Follow O&M principles - System communicates necessary information effectively to enable users to navigate independently to destination

Design Principles

• Tolerance for Error: If user misses landmarks the system redirects the user to destination

• Low Physical Effort: Smartphone based

• Size and Space for Approach and Use: Smartphone and Vision Free user interface (“Talkback”)

• Pre-journey learning and training

Outline

• Introduction• PERCEPT in MBTA Subway• Demonstration• Trials• Conclusion

PERCEPT at MBTA

• Deployed PERCEPT at Arlington Station– On Green Line– Downtown Core Station (Heavily Utilized)– Next to Boston Commons

• 4 Entrances• 2 Subway Platforms• 2 Restrooms• 1 Information Booth• Elevators, Escalators,

& Stairs

Components

• PERCEPT Space– NFC tags deployed in environment• Require no power source• Inexpensive

– Digital space mapping– Instruction generation algorithm

• PERCEPT Smartphone application• No Internet required when providing navigation

instructions• Accessible interface to blind - “Vision Free”

What is NFC?

Many of us most likely use this technology throughout our daily life

– E-Z pass• Pass in your car is the tag• Toll booths have readers

– Anti Theft Systems in Stores• Items are tagged• Entrances have readers

– Apple Pay• Smartphone mobile payment

• NFC Tag– Requires no power source– Ruggedized (harsh weather, temperatures,

chemicals, tampering)– Inexpensive ($5)– NFC reader available on most smartphone

(iOS SDK pending)

• Deployment– We collaborated with O&M to determine

optimal tag placement in the environment

NFC Tags and Deployment

MBTA Tag Placement

MBTA Tag Placement

O&M instructor determined proper placement of tags in Arlington Station following ADA guidelines

Consistent Tag Placement

48 in.

2 in.

Entrances

Floor

48 in.

2 in.

Change in Texture

Floor

Fare Gate

Fare Card Scanner

NFC Tag

Floor

PERCEPT Space

• Designed sensory roadmap • Developed a set of rubrics that follow O&M principles• Rubrics are applied to our Automatic Navigation

Instruction Generator

BeepingMetal

Beeping &Opening/Closing of

gates

MetalTileStairway

Hallway inclines

PERCEPT Application

• Download from Google Play• No Internet required when

providing navigation instructions• Accessible “Vision Free” interface

for blind and visually impaired– Utilizes Vision Free Accessibility

Service “Talkback” in Android, Similar to “Voiceover” in iOS

• User interacts with PERCEPT as they would with other applications on phone (e.g. mail, web browser, music, ect…)

Vision Free User Interface

• User navigates the application by performing touch gestures on the screen – Touch: Item touched is read to user– Swipe Right or Down: Select Next Item– Swipe Left or Up: Select Prior Item– Double Tap: ‘Clicks’ selected item

Entrance: Boston GardensEntrance:Arlington StreetDestination set

to Entrance Boston Gardens

Android Talkback Services, similar to “Voiceover” in iOS

Start Application Select Destination Scan Tag Receive Instructions

Smartphone App Flow

Outline

• Introduction• PERCEPT in MBTA Subway• Demonstration• Trials• Conclusion

DEMONSTRATION VIDEO

Outline

• Introduction• PERCEPT in MBTA Subway• Demonstration• Trials• Conclusion

Trials Overview

Two Phases

Phase A Phase B

- Five visually impaired subject test PERCEPT in Arlington station

- Returning Subjects from Phase A and five new subjects

Improvements to PERCEPT based on trial feedback

Time

Phase A Trials

5 Visually ImpairedSubjects

Navigate Throughout Arlington Green Line Station

Using

Trial Composition

Hands-on Orientation• Sit-down & on-site

4 Destinations• Unique entrance to a

subway track• Subway track to unique

entrance

PERCEPT Trial

??? Post Trial Questionnaire

• Questionnaire to obtain:• Subjects feedback and experience• Qualitative evaluation of PERCEPT

Hands On Orientation

Each subject was given a two part one-on-one orientation to PERCEPT

Part 1 - Sit Down – Instructor:

• General introduction of PERCEPT space and PERCEPT app– Subject:

• uses PERCEPT App while sitting down trying out all functionality– Questions and answers– When subject is comfortable continue to Part 2

Part 2 - On-Site (at Arlington Station)– Subject:

• uses PERCEPT App in an Arlington station along routes that will not be in the trial

– Questions and answers– When subject is comfortable the trial will begin

PERCEPT Trial

• PERCEPT trial is composed of four tasks

• Subject is asked to complete these tasks while only relying on their mobility skills and PERCEPT App

• Instructor is no longer able to answer any questions or assist subject during the trial

• Trial ends either when all tasks are complete or subject decides to stop

PERCEPT Trial Task 1

Entrance 9 to outbound platform using stairs

PERCEPT Trial Task 2

Outbound platform to entrance 6 using stairs

PERCEPT Trial Task 3

Entrance 5 to inbound platform using escalators (when available)

PERCEPT Trial Task 4

Inbound platform to entrance 9 using escalators (when available)

Post-Trial Questionnaire

Subjects were asked to answer the following statements with a 10-point scale. 1(strongly disagree) to 10(strongly agree)

a) Easy to learn how to use the system b) Easy to use the systemc) Trial design was easy to completed) Easy to use User Interface e) Easy to find the R-tags

Subjects were asked to give their impression on the following:

1) Likes/dislikes of the system?2) Name the most difficult part of using the system3) Name the most difficult part of the trial4) Level of confidence in self – How confident were you when the trial started, that you could accomplish the task successfully?5) Are there some improvements you’d suggest we make to the system?6) Based on your experience using PERCEPT if you were to come to an PERCEPT enabled subway station in the future, would you use it?

Revisions to PERCEPT based on Trial Feedback

• Enhanced the Application by providing additional context to entrances and a reminder to the user on selected destination

• Modified navigation instructions in some locations

Trial Overview

Two Phases

Phase A Phase B

- Five visually impaired subject test PERCEPT in Arlington station

- Returning Subjects from Phase A and five new subjects

Improvements to PERCEPT based on trial feedback

Time

Phase B Trial

• Currently In Progress– Identical Trial Structure as Phase A

• Six visually impaired subjects so far have performed Phase B trial– Three returning from Phase A– Three new to PERCEPT

• All six were successful completing all tasks within the station using PERCEPT– Returning subjects loved the changes– All subjects thought the app is ready for public use

System Scalability

• Easy to Learn how to use system scored an 8.29/10

• Most subjects felt PERCEPT was very easy to learn and use – Some requiring less than 10 minutes of orientation to use the system– Average orientation time 30 minutes – A significant portion of orientation time was spent familiarizing

subject with Android Accessibility, instead of actual PERCEPT app itself

• We are continuing to improve usability of app through feedback received in trials

• We developed a set of training videos to orient users without the need of human training

Outline

• Introduction• PERCEPT in MBTA Subways• Demonstration• Trials• Conclusion

Conclusions

• Easy to use• Cost efficient for both users and transportation venues• Scalable• Pre-journey learning option• PERCEPT Web Service extends functionality beyond the

smartphone– Users without smartphone can use service to plan out their

journey and print the navigation instructions out in large print or Braille

– In addition the instructions can be synthesized into an MP3 file so that it can be played on a users music device

Thank You

Professor Aura Ganz– ganz@ecs.umass.edu

– http://5g.ecs.umass.edu/

– http://www.perceptwayfinding.com/