This is a type of overlap that is shorter than a full overlap in length. This may in fact be no overlap (and thus no length) at all. The preceding signal will be held at red until a train is close to stopping at that signal, whereupon it will clear to a single yellow. Also known as a Delayed Yellow sequence. The Route itself is called a Warner route.
Last edited by GeoffM on 15/09/2016 at 03:01