Thanks Spud. In reading the thread at Orbx, it looks like a lot of people had trouble with their patch for some unknown reason. I tried it, installed fine, but it only slows freeways down to 55 MPH, which is only 5 MPH slower than default, and the buggers still go too unrealistically fast for my taste. It's an easy fix to adjust things slower using the Orbx file however. If anybody wants to know how, let me know here.
Steve