Oh BTW, the US has plenty of restricted areas, and a whole bunch of prohibited ones as well.
Yes but most of what we call 'restricted airspace' in Oz, in the US is actually an MOA and you are able to transit these without a clearance! It is prudent however to make contact while transiting!
Restricted and prohibited areas are saved for firing ranges and areas of political sensitivity, they are in general very small, not great chunks of airspace along the major East Coast trunk route!
