USA Overflights
 

It has been said that al Qaeda might use an international flight that overflies the US in a terrorist attack. Presumably, wherever this flight departs does not check passengers thoroughly such that the crew could be killed and the a/c commandeered.

I was just curious about how many flights, scheduled or otherwise, cargo or pax, overfly the US in a typical day and generally from where to where do these flights originate and terminate?