To draw
straight track:
You have a point-to-point railroad! If you wanted to, you could add a train and start operating.


You now have a continuous section of road with a bend in the middle.

To draw a switch:
A
switch is automatically created whenever three tracks join. This happens
when you begin or end drawing a segment at either an existing junction or a
point along an existing track.
To draw the switch shown here:
OR:

As soon as you release the mouse button using either method, the switch is created and the stop/go lights appear. You can test the switch by clicking at B.
To draw
a multi-way switch:
Simply draw more than three segments to a switch. Whenever more than three segments join, a multi-way switch is formed with more than two routes through it. Each throw opens a different route.
In this picture, the current open route is A-B-D. The first throw opens route A-B-C; the second, E-B-D; the third goes back to A-B-D.
To
draw a crossing:
Draw tracks which cross but do not join. In this example, AB and DC cross each other, but there is no junction in common, so trains cannot go from one track to the other.