Peter Smedskjaer-Stenland Feb 4, 2013:

Which it is, siding, switch or junction, or other term, is dependent on context, and unfortunately, I do not mean the context of the source text. A siding should be thought of as, and I am over simplifying by a gross margin here, as the on/off ramp for a highway onto a road, or more accurately, a surface street, and if it is a siding into an industrial park, it can be connected to the mail line at only one end and be analogous to a dead end street.
The safest two terms for you in this case will be 'railroad switches', or because the text is seemingly technical in nature, turnout.
Junction is often popular, but you need to keep in mind what is macro and what is micro. Junctions are not the switches themselves, but the location for the switch or points.
So, a rundown.
Junction - Macroscopic, location for a switch or points, often with a name.
Switch - Microscopic, the physical connection between two or more rail lines, and rarely named.
Points - Microscopic, plural form of switch in rail terminology.

Hope this helps.