Depends on the brand of track and the tuning of the cars. I have some HO slot cars that can run lap after lap on a well built track even in plastic, and on a routed track you have control of the slot depth and width, and the curve radius. I seldom run the cars with magnetic attraction to the rails, so they are easier to control in my mind. You will get more car detail with 1/48 or 1/32, but less track per square foot, and you would need to custom build a railroad crossing in either of those if you wanted to have that in your layout. In HO many brands have railroad crossing tracks, which I loved as a kid, but did not build into my current layout. There are a number of cottage purveyors of HO slot car equipment whether you are going for authenticity or racing. There probably are a number as well in the larger scales, but I have not followed them although I do have one small 3 x 6 layout for running cars of the larger scales if I want to.
This is the HO 24 Hours of Le Mans video
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Here is the best track anywhere in HO...the KatzSpaRing. You will note the host is now on "Dirty Jobs", and the sadly, the builder of the track, Greg Katz, has passed away. His track in now part of the San Francisco HO Racing Association.
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