In the image, the tracks are from top to bottom: This can sometimes cause a "no path" error where the track appears to be connected, but part of the connection is a one way track. A train in automatic mode will not drive on a track if it would pass a signal on the left side unless there is also a signal on the right side at that signal. Trains are only allowed to go past signals that are on the right hand side from direction of travel. Signals are placed on the right side of the track. When a train is in the process of entering the block, the signal turns yellow for a short time before turning red. When a train enters the block, all signals going into the block will turn red. Rail signals (and chain signals) break up blocks, train stops do not.Ī regular signal is green when there is no train on the block behind it. The picture shows the block visualization, there are a total of eleven blocks. Rail blocks are shown with colors when a player has a signal in hand. Whenever a second train would enter a block that already has a train in it, the train will wait at the signal leading into the block instead. Signals ensure that only one train can be in any block. A regular rail signal protects the rail block after it, up to the next signal or the end of the track. To prevent trains from doing this, we place signals at intervals along the track and at crossings. Whenever there is more than one train on a track, there is the possibility that trains can crash into one another.