The biggest problem with Lionel Fastrack is that it is much louder than tubular and other types of O gauge track. So people frequently ask how to quiet Lionel Fastrack. There are a few things you can do to make Fastrack quieter.
The problem is that the hollow plastic roadbed amplifies the sound of the train running above it. It behaves much the same way as a guitar body. Making matters worse, if you mount it on a table, the table probably acts like a guitar body as well.
The trick to quiet it down is to cut a piece of carpet padding, or better yet, a Mr. Clean Magic Eraser or knockoff, to fit underneath the track section. Place it underneath the track section before you secure it to the table. Magic Eraser is actually a soundproof mat; its cleaning properties were a happy accident.
When you fasten the track to your table, don’t use metal screws. Drill a hole, then slide a zip-tie through the hole in the track into the table. Then from the underside, secure a second zip-tie to the one coming from above. Nylon conducts sound much more poorly than metal.
Finally, rather than putting Fastrack right on top of a wooden table, put a layer of Homasote in between the track and the table. Homasote absorbs much of the sound that gets through the carpet padding.
Even after doing these things, Fastrack tends to be a bit louder than traditional track, but it makes the noise tolerable.