[borisblat]

Is it Possible to do it?
like put rail lines underground and spawn a train there?

[Djiango]

No. Train tracks are coded in data files, which you can find inside the "GTA San Andreas\data\Paths" folder.
I wouldn't advice changing any of the files, unless you're absolutely sure on what you're doing.
I did a little railroad track once, but nothing that would work over network.

[borisblat]

Ok. thx.