Section 18.4 - PLATFORM ACCESSTo facilitate access to subway cars, airplanes, buses, trains, and other means of public transportation, platforms shall comply with the following:
18.4.1 Platform to Vehicle Gaps: At newly constructed, reconstructed, altered, or remodeled stations, the distance between platform and vehicle at boarding platforms shall not exceed three inches (3" = 76mm) in the horizontal plane and 1/2 an inch (1/2" = 13mm) in the vertical plane. Where construction constraints result in platform to vehicle gaps that exceed these requirements, a bridge plate designed to eliminate such gaps shall be made available at every door of the vehicle where passengers are boarding or disembarking. Where construction constraints in light rail stations result in platform to vehicle gaps that exceed the requirements a device used to bridge the gap must be a minimum of 36 inches wide or the width of the opening, whichever is greater and the slope shall not exceed 1:12. Exception: a slope between 1:10 (10%) and 1:12 (8.3%) is allowed for a single rise of a maximum of three inches (3" = 76mm).18.4.2 Platform Warnings: Platform edges at newly constructed, reconstructed, altered, or remodeled stations shall have a yellow (Federal Yellow 33538) band of detectable warning at least 24 inches (24" = 610mm) in width except where there is no defined platform edge, the warnings shall be placed far enough from the tracks to allow for the dynamic envelope of vehicles using tracks at those terminals. See Fig 18a. Click to view image
a.Detectable warnings shall consist of raised truncated domes with a base diameter of nominal 0.9 inches (0.9" = 23mm), a height of nominal 0.2 inches (0.2" = 5mm) and a center-to-center spacing between domes which are farthest apart in a configuration, of nominal 2.35 inches (2.35" = 60mm) and shall contrast visually with adjoining surfaces, by a minimum of 40%.b. The material used to provide contrast shall be an integral part of the walking surface.c.Detectable warnings used on interior surfaces shall differ from adjoining walking surfaces in resiliency or sound-on-cane contact.