Beyond user interfaces in mobile accessibility: Not just skin deep

With the increasing popularity of mobile technologies, users today are able to access information from virtually anywhere. Examples include localization via the Global Positioning System (GPS), Internet access through cellular and WiFi networks, etc. Using assistive technologies, people with disabilities can live more independently than ever before. However, most of the current mobile applications are not developed with accessibility in mind. This paper uses mobile applications for public transit systems as a case study, and presents an extension of our prototype ABLE (Accessible Bussing through Location Estimation) Transit. Based on an estimate of the user's current location, ABLE Transit leverages the location services on mobile devices and public transit information to reveal schedule and route information in accessible formats. We derive four groups of personas that need to be addressed when designing accessible software. While the cross platform accessibility is preserved at the user interface level, we further investigated system level concerns and implemented two data storage strategies for large transit schedule data. We identify the tradeoffs of Web versus native applications, local versus remote data storage when developing assistive technology, and discovered that accessibility at system level is particularly challenging.