Using Smartphone App to Help the Visually Impaired Navigate Work Zones Safely
Chen-Fu Liao, Senior Systems Engineer, Mechanical Engineering
According to statistics from the Federal Highway Administration (FHWA), each year approximately 17 percent of all work zone fatalities are pedestrians. Pedestrians who are visually impaired often encounter physical and information barriers that limit their accessibility and mobility. A survey was conducted among 10 visually impaired participants as a starting point to understand their challenges and what type of information is helpful in providing bypass or routing instructions to them around work zones, and the survey results were incorporated into the development of guiding documents.
Building on previous efforts to provide geometry and signal timing to the visually impaired at signalized intersections, a smartphone-based navigation system was developed and integrated with navigational audible information to alert pedestrians at decision points prior to their arrival at a work zone. The recommended message elements from survey results were implemented in a smartphone app that uses GPS and Bluetooth technologies to determine a user's location. When a work zone is detected, the smartphone will vibrate to alert users and the app will then announce a corresponding audible message to users. The visually impaired user can perform a single tap on the smartphone to repeat the messages, if needed. Functionality testing and system validation of the smartphone app were performed by attaching four Bluetooth beacons to light posts near a construction site in St. Paul, Minnesota. Additional research is needed to conduct experiments with visually impaired users and evaluate system reliability and usefulness.