The train doors were originally designed to be opened and closed automatically and the doors would re-open if an object blocked them, much as elevator doors do. Almost immediately after the system opened in 1976 Metro realized these features were not conducive to safe or efficient operation and they were disabled. Metro began testing reinstating automatic train door opening in March 2019, citing delays and potential human error. If a door tries to close and it meets an obstruction, the operator must re-open the door.