How to make a func_train:

1. Create a brush with the block tool. Press CTRL+T and choose func_train. Write in "first stop target" the name for the first stop target. link

Note: You can change the speed of the train if you want.

2. Create stop targets whit the entity tool and make them like this:

path_corner 1:
Name - stop
Next stop target - stop2

path_corner 1:
Name - stop2
Next stop target - stop3

link

Note: You always can play with the other options.