I've thought of another improvement too: with track markings, less is more...
A single (or two right next to each other) is totally adequate to separate two parts of the track - no need for empty 'islands', even for marshalls, they always find a suitable space to stand, in a corner of the track etc.
Look how simple that is, looks awesome, clear, simple, no wasted space. I bet it results in some awesome racing.
(From
http://eos.redrc.net/series/)