Dimensional Tolerances in Construction and for Surface Accessibility

Original research for ANSI A117.1 (1957 - 1961)
In the original research for ANSI A117.1 - 1961, American National Standard Specifications for Making Buildings and Facilities Accessible to, and Usable by, the Physically Handicapped, ramps were assessed for flatness based on measuring 18 - inch increments on both edges of the ramped surface. Both slope and cross slope were measured. These guidelines for measurement were deleted from later versions of the standard.