I have probably run across a partial answer in a forum but have read so many my head is spinning.
LISTA - Route, Mileage (calc'ed from Route), Zone (calc'ed from Route).
LISTB - Route (lookup from ListA), Mileage (lookup from ListA), Zone (lookup from LISTA)
Now, on my NewForm.aspx for ListB, I want the users to select Route from the dropdown (this is working fine), BUT based on that selection I want to DISPLAY (non-editable) the mileage and zone.
This is probably extremely simple, but I have looked at it too long.