PedPal: An App to Make Street Crossings More Inclusive

Client: Carnegie Mellon University
Date: May 2017 through November 2019
Services: Emerging Technologies, Spot Checks, Wayfinding, Inclusive Design Gap Analysis

PAC worked with Carnegie Mellon University to design and build PedPal, an iPhone application that connects with smart traffic signals via DSRC or cellular networks to help disabled pedestrians assess crossing time, request more time where supported, and navigate signalized intersections more safely.

Project Description

PAC worked with Carnegie Mellon University to design and build PedPal, an iPhone application intended to support safer pedestrian navigation at signalized intersections in smart city environments.

PedPal was developed to communicate with smart traffic signals using the transportation communication protocols that support connected infrastructure, including DSRC. Through that connection, the application could let a traveler know whether there was enough time to cross an intersection and, where supported, request additional crossing time to make the crossing safer and more manageable. PedPal was also designed to work over cellular networks, allowing these interactions to happen on a user’s phone without requiring dedicated external hardware.

The project addressed a significant challenge in accessible wayfinding: crossing an intersection is not only about knowing when the pedestrian signal is active. Disabled pedestrians may also need information about the geometry of the intersection, the direction and length of the crossing, signal timing, and whether they are maintaining the correct path of travel. PedPal explored advanced localization approaches to help provide that information accessibly, including feedback that could help a traveler understand if they had veered off course during the crossing.

PAC built the application and supported its development as a practical, user-centered tool for accessible navigation. The project also included user testing conducted by the research team, helping evaluate how the application performed for real users in relevant travel contexts. The broader vision included integration with public transportation tools and existing accessible wayfinding applications, demonstrating how smart city infrastructure, mobile technology, and inclusive design could work together to provide disabled pedestrians with better information, greater confidence, and more equitable access to public space.