Minimum distance between tracks

I am putting a shelf around the ceiling, what is the minimum distance you would recommend between 2 ovals. Using LGB and Aristocraft track, I sure hope I can get by with 2" distance between ties, I can offset the curves so their isn’t a problem. Please comment, THANKS

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this is 9’ 10’ and 11.5 diameter track. the black toped car is aristo coach the other is a aristo baggage on the 9/10 combination. Try your longest cars to see what your minamum spaceing is. hope this helps