Research Article Supporting Accessibility for Blind and Vision-impaired People With a Localized Gazetteer and Open Source Geotechnology Matthew T. Rice Department of Geography and Geoinformation Science George Mason University Ahmad O. Aburizaiza Department of Geography and Geoinformation Science George Mason University R. Daniel Jacobson Department of Geography University of Calgary Brandon M. Shore Department of Geography and Geoinformation Science George Mason University Fabiana I. Paez Department of Geography and Geoinformation Science George Mason University Abstract Disabled people, especially the blind and vision-impaired, are challenged by many transitory hazards in urban environments such as construction barricades, tempo- rary fencing across walkways, and obstacles along curbs. These hazards present a problem for navigation, because they typically appear in an unplanned manner and are seldom included in databases used for accessibility mapping. Tactile maps are a traditional tool used by blind and vision-impaired people for navigation through urban environments, but such maps are not automatically updated with transitory hazards. As an alternative approach to static content on tactile maps, we use volunteered geographic information (VGI) and an Open Source system to provide updates of local infrastructure. These VGI updates, contributed via voice, text message, and e-mail, use geographic descriptions containing place names to describe Address for correspondence: Matthew T. Rice, Department of Geography and GeoInformation Science, 4400 University Drive, MS 6C3, George Mason University, Fairfax, VA 22030-4444, USA. E-mail: rice@gmu.edu Transactions in GIS, 2012, 16(2): 177–190 © 2012 Blackwell Publishing Ltd doi: 10.1111/j.1467-9671.2012.01318.x