I'm really new to model RR'ing and don't under stand.  do you mean EZ track or something else.  I have mostly black plastic ballast but I do have some gray plastic ballast that I think is nickle.  Help me.

I have an older train set with "power lok" track.  It is not compatible with the newer EZ track.  Can I still get new pieces of track for my set or do I need to buy new trackage.  I would like to expand my layout from an oval to a more complicated layout.  I will need some switches and smaller diameter curved track plus other pieces.