Second Generation Accessible Pedestrian Systems
Wall, Richard W.
Bauer, Denise H.
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The Americans with Disabilities Act of 1990 has had a great impact on the implementation of Accessible Pedestrian Systems that target accessible and safety impediments faced by pedestrians with mobility and visual impairments. Intersection geometries are not uniform, and the traffic signal timing varies widely from one intersection to the next as well as days of the week and even hours of the day. The customization of the traffic signal operations is generally oriented to improving the performance of the vehicular traffic; the resulting changes in traffic patterns almost always impact the pedestrian access. Longer cycle lengths require pedestrians to cope with inclement weather or become impatient resulting in crossing without a WALK signal. For pedestrians who have vision impairments, the challenges become daunting. No longer is vision the primary means of communicating information that directly affects the safety when crossing a street. To allow safer and more reliable pedestrian access at signalized intersections, the pedestrian systems should be able to be customized easily and quickly. Pedestrians can be faced with confusing or conflicting directions resulting in unsafe actions and could be tempted to assume increased individual risks if there is no ability to tune the pedestrian information for each intersection. . These systems are intended for use by pedestrians possessing a wide range of physical and cognitive abilities, and our research seeks to provide direction and alert these pedestrians of potential dangers in ways that are clear and quickly comprehended. This research leverages off Smart Signals Research that started in 2004. The goal from the beginning was to develop a system that can provide capability for advanced technologies to improve the safety for pedestrians at signalized intersections. At early stages in this research, it was realized that the technologies currently being used do not provide the necessary infrastructure. Hence, past research focused on an enabling technology that has resulted in an innovative highly customizable pedestrian control system that has been commercially offered to a national market since 2010. Feedback from transportation agencies, pedestrian advocacy groups, and transportation equipment manufacturers has directed the research in areas that can provide the enhanced capabilities for precise and reliable systems to assist the general pedestrian population. Through workshops with an advisory group, extensive dialogs with experts, and technology development, we have developed a second generation of accessible pedestrian systems capable of being expanded to include direct interaction with selected pedestrians. We also conducted a pilot test to determine an appropriate tone for our second speaker navigation. Technical reviews involving the research designers and the engineers with equipment manufacturers for the first generation pedestrian control system hardware and software brought out several key elements that needed improving. The hardware and software underwent extensive redesign, testing and performance evaluation. The resulting equipment has lower cost and improved capability and performance. The major system design improvements are wider operating temperature range, independent audio outputs, simplified power circuit design, extensible communications capability using diverse wireless and direct wired network technologies, and equipment that is less expensive to install. The results of the pilot testing gave us direction for future larger-scale testing and insights on how individuals cope without vision. The benefit of the advanced features will be realized when the pedestrian navigation and guidance features are integrated with the second generation hardware.