none
Every Lionel Train ever built will run on every type of track produced, including FasTrack.
Lionel Fast Track is designed specifically for Lionel trains, and its track system may not be compatible with Marx trains, which typically use a different track gauge and design. While some hobbyists have found ways to connect different brands, it's generally recommended to use the appropriate track for each train brand to ensure proper operation and avoid damage. Always check the specifications of both the track and the trains for compatibility.
No because they use different currents, track sizes, and power methods (2 and 3 rail).
Oh that would be tough... But if you are in member of a same forum you can track on his posts and reputations though this is really not an assurance.
No. Lionel is approximately O gauge (1/4 inch to the foot) and S gauge is 3/16 inch to the foot. Lionel has taken a number of liberties in "scaling" their models - some are quite close to accurate but most are not.
All model trains are compatible on the same track if they are the same gauge. The only time they may not be compatible is if a dcc chip is programmed not to run on dc.
train track
A replacement Lionel Train track costs about $160. One can go to the official site of Lionel for purchase. However, one may try ebay and amazon for cheap deals.
Railroad
railroad
Siding
Siding