You mean train sway right? That's when the cars sway from side to side. That is something that you need to code into the route file.
Look into the route file (use find in notepad / wordpad) and find a line that says something similar to this:
.adhesion 255,.back 2,.ground 1,.height 8.8,.pitch 0,
Add .accuracy 4 after the .adhesion line so it'll look something like this.
.adhesion 255,.accuracy 4,.back 2,.ground 1,.height
Change the 4 to a number lower (cause 4 is the max amount of sway you see) for more minimal amounts of sway.