People with vision impairment rely heavily on walking and public transit for their transportation needs. A major challenge for this population is crossing intersections safely. As a result of the Americans with Disabilities Act, accessible pedestrian signal systems at signalized intersections have improved significantly since 2000. However, these systems still have shortcomings for both users and municipalities, and new approaches are needed to serve pedestrians with low vision adequately. As part of the ongoing effort to develop a prototype mobile accessible pedestrian signals (MAPS) application for the blind and visually impaired, 10 blind and low-vision people were interviewed to understand better what types of information they use at intersection crossings and to identify the types of information that could assist them. With these survey results, a MAPS system was developed to provide signal and intersection geometry information to smartphone users at signalized intersections. User interaction was with simple tactile input (single or double tap) and text-to-speech technology. A field experiment at two signalized intersections was conducted with 18 visually impaired participants to validate the use and functioning of the MAPS system in a real-world application. The purpose was to identify whether the smartphone application could effectively provide geometry and signal timing information and thus provide decision support for visually impaired pedestrians. Objective and subjective measures were developed to evaluate the performance of visually impaired users of MAPS. Participants reported that the MAPS system provided helpful geometry information (82%) and helpful signal information (59%).