Model railroads.

What type of track are you using, Fisher? Brass or nickle silver? 3' long sections or short ones? Long term, soldering the rail ends together and using a 'track cleaner' (an 'eraser' looking thing) will contribute a lot to smoother and more reliable operation.

I assume that cork roadbed with a layer of ballast is still the way to simulate a raised roadbed....

All of which you may already know.