Tactile Wayfinding in Transportation Settings for Travelers Who Are Blind or Visually Impaired: Volume 1: Conduct of Research (2025)
Chapter: Glossary and Abbreviations
Glossary and Abbreviations
| ASLA | American Society of Landscape Architects |
| COMS |
Certified orientation and mobility specialist. An individual who teaches concepts and skills for independent travel to people who are blind or who have low vision. Certification is by the Academy for Certification of Vision Rehabilitation & Education Professionals (ACVREP) after individuals successfully complete a specialized degree program, internship, and exam. |
| CPI |
Choice point indicator. An empty or blank space at the junction of TDI paths that is 3 ft (0.9 m) square to indicate the location of intersecting paths (see Figure 9, item C). |
| DWS |
Detectable warning surface. A standardized surface comprising truncated domes indicating the boundary between a pedestrian path of travel and a vehicular way, such as at curb ramps, blended transitions, and along the edge of transit boarding platforms. DWSs are attention fields that function like stop lines, indicating to the pedestrian to check for a hazard directly ahead before proceeding. Previously/also known as: detectable warning panel or strip, truncated domes (see Figure 2). |
| ISO |
International Organization for Standardization |
| NACTO |
National Association of City Transportation Officials |
| NIDILRR |
National Institute on Disability, Independent Living, and Rehabilitation Research |
| PAR |
Pedestrian access route. An accessible, continuous, and unobstructed path of travel for pedestrian use. |
| TDI |
Tactile direction indicator. A surface comprised of raised parallel flat-topped elongated bars. Previously/also known as guidance strip, raised bars, detectable guidance surface, wayfinding strip (see Figure 3, TDI-1). Guide bars: 12-in-wide (0.3 m) TDI defining an unobstructed path of travel in the direction of the bars. The bars are oriented in the direction of travel, and the pedestrian is expected to follow them (see Figure 18). Sidewalk alert bars: a 24-in. (0.6-m) wide TDI across the width of a sidewalk or walkway to indicate the location of a noncorner crossing or transit stop, and to provide a reliable cue for aligning to cross or to board. The raised bars are oriented perpendicular to the direction of travel across a crosswalk or onto a transit vehicle so they provide an accurate cue for aligning to cross or board. (See Figure 21) |
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Alignment bars: a 2 × 2 ft (0.6 × 0.6-m) square of TDI that provides an accurate alignment cue for crossing a street where other tactile or audible cues are absent or misleading. The raised bars are oriented perpendicular to the direction of travel across the associated crosswalk (see Figure 23). Transit door location bars: a 2 × 3 ft (0.6 × 0.9 m) rectangle of TDI, with the 2-ft (0.6-m) side parallel to the curb or platform edge, to indicate where transit boarding doors open. The raised bars are oriented perpendicular to the direction of travel onto a transit vehicle. At rail stops, and at bus boarding areas on a platform raised above standard curb height, the transit door location bars will be flush with the DWS at the platform edge (see Figure 16). At bus stops at curb height or lower, the bars will be flush with the curb. |
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| TWD |
Tactile warning delineator. A surface comprised of a raised trapezoidal shape in cross-section. Used to delineate a boundary between a pedestrian area and a vehicular area; indicates there is a vehicular hazard on the other side, such as a bicycle path, transit line, or other mode, and is an edge treatment not to be crossed. Previously/also known as a trapezoidal delineator (see Figure 10). |
| TWSI |
Tactile walking surface indicator. Generic term for types of walking surfaces, such as DWS, TDI, and TWD, to aid wayfinding for pedestrians who are blind or have low vision. |
