The battle over installing bumpy tiles at Metro’s stations has been going on for about 20 years, long after the Americans with Disabilities Act called for adding “detectable warnings” known as truncated domes to platform edges in train stations by 1993.

Metro board member Mortimer Downey recalled the agency’s resistance when he served as U.S. Department of Transportation deputy secretary from 1993 to 2001. “Metro wasted two years of my time telling me they did not want to put in the tiles and did not think it was feasible to do it,” he said during a recent board meeting.