Operating question

[foulrift]

I have a question concerning layout operation. My switching layout has 2 small yard tracks and I would like to know if these tracks should be left empty prior to starting a switching session? The A/D track holds 4 cars without fouling the roadway that crosses the track. Should one of both of these yard tracks be left open to aid in switching cars in and out of the industries?
Thanks for any help.
Bob