Traffic systems should avoid having trains waiting on crossings and in Factorio, Rail chain signals are used to ensure that this cannot happen. These trains may in turn cause other trains to wait, resulting in a slowdown of the entire system. If a train waits on an intersection, other trains have to wait for it, even trains that are not going in the same direction. bidirectional on the left side, splitting into a right to left (upper) and a left to right track (lower).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 through 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. To allow trains to go in both directions one either runs two rail lines in parallel or puts signals on both sides of the track. Signals are placed on the right side of the track and trains are only allowed to go past signals that are on the right hand side from direction of travel. When a train is in the process of entering the block, the signal turns yellow shortly before turning red to inform that the block is reserved for the incoming train even though there is no train inside it. 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 in an example, there are a total of eleven blocks. These colors are only for visualization of blocks and are not related to the color of the signal light. Rail blocks are shown with colors on the rails themselves when a player has a signal in hand. Any signal leading into an already occupied block will display the red color and trains that would enter will wait at the signal instead. The signals then ensure that only one train can be in each block. Signals split the tracks into different parts called blocks.

To prevent this, we place signals 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. 2.1 Splitting rail blocks and increasing throughput.Finally, players should choose a maximum train length before designing a rail system. Trains can either be fueled at one stop on their usual schedule (this may or may not involve transporting fuel to a station) or by adding a separate fuel station to the schedule. It is also recommended to set up automation for fueling trains as soon as possible whenever a new train or station is added to the system. It is recommended to place radars near intersections to help identify issues quickly. For beginners, using this architecture is suggested instead of a single bidirectional rail line, which can lead to issues when more trains are added to the system. This tutorial mostly uses rail systems with two parallel rails, one for each direction. Examples of frequent issues and use cases are shown. The aim is to enable the reader to keep a rail system running smoothly and fix common issues. This tutorial explains why and how signals are used, how chain signals work, what deadlocks are and how they can be avoided. Rail signals are necessary to run a functioning rail system in Factorio.

Factorio train signals