This project evaluates the effectiveness of Universal Crosswalk Diagrams (UCD), a new kind of street sign to aid pedestrians who are blind or have low vision. These small signs are mounted directly above existing Accessible Pedestrian Signals (APS), the pole-mounted buttons at street corners that pedestrians press to request information about the current status of the Walk/Dont Walk indicator. Each sign shows a raised-line diagram of the street about to be crossed, with tactile symbols for You Are Here, vehicles, medians, turn lanes, etc. A thick dotted line indicates the direction of travel to cross the street. The pedestrian can examine the diagrams before crossing to determine the distance to the far corner and to preview the route. As an additional feature, each sign includes an embedded Bluetooth transmitter with a unique identifier code, enabling the pedestrians smartphone to provide an accessible description of the street crossing in speech or Braille when in close proximity to one of these signs. Phase 1 research and development includes prototyping UCDs for two intersections in San Francisco, culminating in a usability study comparing inferences about intersection layout made by eight users with visual disabilities, with and without use of the proposed signs.
