Rail Building
  Part 6: Check Points

Ever built a complicated railway network and then had the problems of your trains getting lost? You're not alone, and TTDPatch and OpenTTD have come up with ways to help deal with these problems.

TTDPatch - new non-stop handling

TTDPatch introduces a feature whereby the behaviour of the non-stop option in the vehicle orders list is altered. In standard TTD, a non-stop order would result in a train only stopping at the stations in the order list, bypassing all others. TTDPatch changes this so that the non-stop option makes trains not stop at any station with that order set.

For instance, take the following track layout:

In classic TTD, sending a train from station 1 to station 3 without the non-stop option would result in it stopping at station 2 as well. Using the non-stop option on the station 3 order, the train would pass through station 2 without stopping.

In TTDPatch, with the nonstop patch enabled, the first of these scenarios would behave the same, but the second scenario - selecting the non-stop option on the station 3 order - would result in the train not stopping at station 3 either. Later versions of TTDPatch will specifically change the order text to read Route through. Now, if you've not planned your game with this distinction in mind, then the non-stop patch can cause problems, but it can be really useful if you've got a complex network and want to set up checkpoints.

A checkpoint is just a simple one-square long station that you place in your network:

If you find that trains will often get lost at a particular point in your network, simply build a checkpoint in the vicinity of the area that the trains get lost at (along the correct route, of course!), and add that checkpoint to the train's orders, using the non-stop option. The trains will head to the checkpoint, but pass straight through it, savings you hours of headaches as you try to sort out a clogged up network due to a train getting stuck down the wrong line!

The TTDPatch wiki has more information on the non-stop feature.

OpenTTD - waypoints

OpenTTD introduces a dedicated waypoint feature. Waypoints can be built using the Waypoint tool on the Railway Construction toolbar:

You can then simply assign a train an order to visit a waypoint in the usual way (no need to select "non-stop"), and the train will pass through it without stopping.

The OpenTTD wiki has more information on waypoints.