AASHTO MP 12-04 pdf free download
AASHTO MP 12-04 pdf free download.Detectable Warning Surfaces.
1. SCOPE
1.1. Detectable warnings provide a distinctive surface of truncated domes detectable by cane or underfoot to alert people with vision impairments of the transition to vehicular ways. These warnings compensate for the sloped surfaces of curb ramps that remove a tactile cue provided by curb faces.
1 .2. It is not the intent of this specification to relieve the supplier from the final responsibility to provide an appropriate product for the intended function, nor is it intended to specify all the design details. The objective is to provide a sufficiently detailed specification that the function is clearly defined to provide a standard geometry of the detectable warning surface.
2.REFERENCED DOCUMENTS
2.1.The Access Board, Accessibility, Guidelines and Standards, 4bRevised Draft Guidelines for Accessible Public Rights-of-Way,” November 23, 2005, www.access-board.gov/prowac/draft.htm.
3.TERMINOLOGY
3.1.detectable warning—A surface feature built in or applied to walking surfaces or other elements to warn of hazards on a circulation path.
4. DETECTABLE WARNING SURFACES
4.1. Genera/—Detectable warnings shall consist of a surface of truncated domes aligned in a square or radial grid pattern and shall comply with the following requirements:
4.1.1. Dome Size—Truncated domes in a detectable warning surface shall have a base diameter of 0.9 in. (23 mm) minimum to 1.4 in. (36 mm) maximum, a top diameter of 50 percent of the base diameter minimum to 65 percent of the base diameter maximum, and a height of 0.2 in. (5 mm).
4.1 .2. Dome Spacing—Truncated domes in a detectable warning surface shall have a center-to-center spacing of 1.6 in. (41 mm) minimum and 2.4 in. (61 mm) maximum, and a base-to-base spacing of 0.65 in. (16 mm) minimum, measured between the most adjacent domes.
4.1 .3. Contrast—Detectable warning surfaces shall contrast visually with adjacent walking surfaces either light-on-dark or dark-on-light.
4.1.4. Size—Detectable warning surfaces shall extend 24 in. (610 mm) minimum in the direction of travel and the full width of the curb ramp. landing. or blended transition.
4.2. Location:
4.2.1. Curb Ramps and Blended Transitions—The detectable warning surface shall be located so that the edge nearest the curb line is 6 in. (150 mm) minimum and 8 in. (205 mm) maximum from the curb line.
4.2.2. Rail crossings—The detectable warning surface shall be located so that the edge nearest the rail crossing is 6 in. (150 mm) minimum and 8 in. (205 mm) maximum from the vehicle dynamic envelope.
4.2.3. Platfbrin Edges—Detectable warning surfaces at platform boarding edges shall be 24 in. (610 mm) wide and shall extend the full length of the platform.AASHTO MP 12-04 pdf download.
