Wash. Rev. Code § 81.112.190
Each authority shall incorporate in plans for stations along any light-rail facility signing that is easily understood by the traveling public, including, but not limited to, persons with disabilities, non-English-speaking persons, and visitors from other nations. The signage must employ graphics consistent with international symbols for transportation facilities and signage that are consistent with department of transportation guidelines and programs. The signage must also use distinguishing symbols or pictograms developed by the authority as a means to identify stations and may identify points of interest along the corridor for persons who use languages that are not Roman-alphabet based. These requirements are intended to apply to new sign installation and not to existing signs, installed before July 24, 2005. The authority may replace existing signs as it chooses; however, it shall use the new signing designs when existing signs are replaced. All signage must comply with requirements of applicable federal law and may include recommendations contained in federal publications providing directions on way-finding for persons with disabilities.
RCW 81.112.190
Intent-Findings-2005 c 19: See note following RCW 35.95A.140.