AUTOMATIC SIGNAL by Metro Digital Resources Librarian • April 14, 2016 A signal that is controlled automatically by certain conditions of the track section that it protects. 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