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.