BLUE FLAG/LIGHT by Metro Digital Resources Librarian • April 14, 2016 Blue flag/light displayed on both ends of a train is an indication that rail employees are on or about the vehicle. Share:Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Tumblr (Opens in new window)Click to share on Reddit (Opens in new window)Click to email this to a friend (Opens in new window)Click to print (Opens in new window)Like this:Like Loading... Related