Is there a feasible way to prohibit or restrict civil AI traffic from restricted airspace (e.g. Nellis Test Range) ?

I don't think so as the FS9 AI aircraft do not follow flightplan points but fly straight A to B.

I once tried creating a scenery file that set up a restricted airspace rectangle over Washington to see what the ai behaviour would be. Much to my disappointment, they flew right through it. Bryn