Have you ever spammed trains to keep up with an industry's production, then had them jam your network when production decreased? Even if you haven't, escape depots can be a helpful tool to alleviate congestion by providing (for all practical purposes) an infinitely large waiting room.

Escape depots are designated as such because they allow trains to escape from a queue when the station does not have an available platform, preventing the queue from extending into oncoming traffic.

Escape depots work by exploiting the pathfinding algorithm function
This function is enabled by default as of January 2024; if you're playing a map created before then, open the console with tilde and enter 'set yapf.rail_firstred_twoway_eol 1'.

The name is fairly intuitive: if a signal at the end of a block a train is in (directly ahead = first) shows red and faces both directions (twoway) the train will regard any track past the signal as nonexistent (end of line = eol). This does not work for path signals, as they cannot be bidirectional.

What we see / What the train sees

Note the signal types - the standard block signal allows trains to freely enter the junction, but any in the depot will wait until a platform is available. This is because the depot has an integrated entry signal reading the status of each exit signal, preventing trains from wandering out.

Escape depots are generally limited to industry stations, where trains are given 'full load' orders. The production rate determines how often trains depart and, by extension, the number of trains needed to sustain said rate. In contrast, passenger services tend to have several intermediate destinations, so departures should be frequent enough to leave room for subsequent boardings. There may be instances where this rule of thumb doesn't apply (I've never found any), so a bit of trial and error might tell you what best synergizes with your network.

As simple as it gets. Easy to build and reasonably efficient, but requires quite a bit of space for broad curves.

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Similar to the roundabout, but trains need to turn around to enter the depot. Since the pathfinder doesn't account for the possibility of turning around, it isn't visible from the main line, so trains seeking maintenance won't get lost. Note the fork on the reverse spur, which the pathfinder needs.

Not much more difficult to build, but a bit less efficient. Recommended when breakdowns are enabled.

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The premier space-saving arrangement. Still not as efficient as the roundabout but much more compact. Ideal for long platforms and multiple cargo types.

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