This description is not structured as a course - it aims to cover the entire subject in its entirety, but only in a methodical and not in a didactic form. If you are new to the traffic screensaver, you might want to start with the Chapter ow to write the Traffic Screensaver Timetable file. That course describes step by step how to use different commands, starting with some very simple examples and with lots of illustrations. That is the recommended introduction, although incomplete as it does not cover the full range of commands and capabilities of the program.
This documentation describes the elements of the timetable file from "top to bottom": It begins with the commands (if you look at an existing timetable file, you will discover how complex the structures can be) and goes down to the individual syntactic elements. You will understand the commands better, especially the move commands, if you follow this section and read all the information about the parts and the available syntax elements.
Many thanks to James McDonald, who revised the first version of this description, not only correcting the linguistic form, but also adding descriptive text about things, that was obvious to the author.