RESNA 27th International Annual Confence

Technology & Disability: Research, Design, Practice & Policy

June 18 to June 22, 2004
Orlando, Florida

Mobile Accessibility Guide

Vince Gibson, John Peifer and Meghna Krishnan
Biomedical Interactive Technology Center,
Georgia Institute of Technology
Atlanta, GA 30318


The Mobile Accessibility Guide (MAG) is a context-aware, mobile wireless application that will provide accessibility information to persons with disabilities. It will alert the user of conditions that may affect travel and provide the capability to receive or document the accessibility of community resources. This approach has advantages over accessibility guides, which can quickly become out of date and cannot be viewed practically on a mobile computer. The MAG combines an online database, contextual information, and mobile wireless Internet technology to provide relevant accessibility information to allow greater independence for wheelchair users.


Context-aware, Accessibility, GPS, wireless, mobile


People who use wheelchairs often encounter difficulties when traveling and trying to locate accessible resources. Barriers along the route may include busy intersections, steep slopes, broken sidewalks, non-functioning elevators, or closed ramps. At the destination, narrow doorways, stairs, high counters, and inaccessible restrooms may block access. While people can find ways to overcome a wide range of barriers, uncertainty about accessibility may discourage people from traveling to new places and reduce spontaneity and independence. Mobile wireless technologies and pervasive computing techniques can be applied to address this problem and to help people who use wheelchairs find accessible routes and resources as they travel. Research is being conducted at Georgia Tech on a Mobile Accessibility Guide that uses wireless technology to keep track of its location and to connect to information networks. The “location-aware” MAG will provide accessibility information and directions to resources in the community. The MAG will also provide accessibility alerts (similar to weather or traffic warnings) when routes or services become inaccessible.

There are many existing access guides that provide accessibility information to people with disabilities (1,2,3). However, online guides are not practically viewable on mobile platforms and printed guides quickly become out of date. A few new hand held navigation applications, such as Vindigo (4), provide general information about the community, but they do not describe accessibility. Contextual information such as, location, user preferences and time, can be very beneficial in computer applications that store, organize, and retrieve information. In their research of context-aware mobile computing, Chen and Kotz found numerous examples of research that have shown context-aware computing to be a useful technology (5). In 1996, Long et al introduced a mobile context-aware tour guide that's goal is to provide information to tourists based on their location and orientation (6). This system does not provide a method for allowing the user to update the information within the system, nor does it allow searching for near by resources. Context-aware navigation systems are now beginning to appear on the market. Although not designed for pedestrians, one of the most widespread location-aware applications in consumer products today is the Global Position System (GPS) in-car navigation system. The TREKKER, a navigation system for blind pedestrians is available that “uses GPS and digital maps to help blind persons find their way in urban and rural areas” (7). These systems do not provide details of accessibility or current dynamic conditions of interest to the user as they travel.


The research hypothesis is that the MAG's combination of accessibility information with mobile context-aware capabilities will increase independence for people with disabilities.


A prototype MAG has been developed that consists of a “client” application running on a mobile wireless device and an information “server” that delivers accessibility descriptions. The current implementation of the server uses Microsoft SQL Server tools to store and retrieve information from the database. The database documents the accessibility of places (such as restaurants, parks, and public buildings) and services (such as transportation, equipment repair, and home health) in the community. These accessibility features are organized in the database by type, location, and time. Database fields attached to these features include ratings, measurements, and descriptive text, audio, and images. Database entries can be created by a registered rating authority or by consumers who enter reviews or annotations as they encounter features in the community. The initial prototype includes data from the Guide to Atlanta for People with Disabilities (2). This guide describes the accessibility of places and services in the Atlanta area and exists in print and as a website. The prototype MAG client software runs on a Hewlett Packard iPAQ running Microsoft's Pocket PC 2003 operating system. A Sprint PCS compact flash connection card inserted into the iPAQ's expansion pack provides a wireless Internet connection. A Pharos Bluetooth GPS receiver is used to acquire the current location. The MAG operates in two modes: 1) an active mode in which accessibility information is requested by the user; and 2) a passive mode in which the MAG continuously monitors changes in the central accessibility database and alerts the user when relevant events occur.

Photo 1. MAG Concept (Click image for larger view) d

In the active mode, the user can request information about the closest accessible place of interest (such as a restaurant, bank or pharmacy). The user's location is retrieved from the GPS component and the MAG compares this location to the location of entries in the database and finds places of interest that are near by. In this active mode, the user can also document accessibility conditions by providing audio, text or images. For example, the user could document a broken sidewalk by snapping a photo and recording a voice annotation describing the problem. The MAG automatically attaches location and time to the user-entered documentation. As these conditions are added to the database, other users of the MAG will be able to benefit from this information. Allowing consumers with disabilities to review establishments and create new entries alleviates the immense task of collecting accessibility information and ensures the information collected is important to the community. For example, Wired on Wheels is an accessibility website that allows the user community to review restaurants for accessibility (1).

In the passive mode, the MAG functions similarly to a weather or traffic alert system. The MAG continuously monitors changes in the accessibility database as the user goes about with daily activities. If a new condition is added to the central accessibility database, the MAG is notified, and the MAG determines whether the new accessibility information is relevant to the user based upon current location, date, time and user preferences. When relevant new accessibility information is detected, the MAG will issue an alert (audio, graphical, or vibration) to bring this to the user's attention. The MAG presents the accessibility condition in a default presentation with a simple description of the situation. If the user chooses to open this alert, the MAG will present additional images, text, and audio with more detailed descriptions of this feature. The user may then decide on a course of action to avoid the area affected.


The Mobile Accessibility Guide is an example of how emerging mobile wireless technologies and pervasive computing can improve safety, independence, and quality of life for people with disabilities. By combining personal profiles with context-aware search and retrieval tools, valuable accessibility information can be made available whenever and wherever needed. In addition, mobile wireless Internet connections enable consumers with related interests to share and expand the database of information.


  1. Wired on wheels. WOW! 13, Nov 03.
  2. Shepherd Center access guide. 13, Nov 03.
  3.'s Guests with disabilities. 13, Nov 03.
  4. Vindigo: location-specific content delivered to mobile devices. 13, Nov 03.
  5. Guanling Chen and David Kotz. (2000). A Survey of Context-Aware Mobile Computing Research. Dartmouth Computer Science Technical Report TR2000-381
  6. Sue Long, Rob Kooper, Gregory D. Abowd, and Christopher G. Atkeson. Rapid Prototyping of Mobile Context-Aware Applications: The Cyberguide Case Study. In the Proceedings of the 2nd ACM International Conference on Mobile Computing and Networking (MobiCom'96) , November 1996.
  7. A GPS System for the Blind and the Visually Impaired. 8, December, 2003.


The research reported here is being conducted under the auspices of the Rehabilitation Engineering Research Center on Mobile Wireless Technologies for Persons with Disabilities (Wireless RERC), funded by the National Institute on Disability and Rehabilitation Research (NIDRR) of the U.S. Department of Education under grant number H133E010804. The opinions contained in this publication are those of the grantee and do not necessarily reflect those of the U.S. Department of Education.

Author Contact Information:

Vince Gibson, MS,
Georgia Institute of Technology,
250 14 th Street,
Atlanta, GA, 30318,
Office Phone (404) 894-7034

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