Strategy Page (a daily read, right?) notes that the missile had been selected at random from the active inventory and transported to Vandenberg (in California) for firing:
This kind of testing is not as realistic as what the Russians do, which is to just pick a missile at random, remove the nuclear warhead and replace it with one full of monitoring and radio equipment, and then fire it. The U.S. can’t do that because American silos are surrounded by inhabited areas. Thus if the missile ran into trouble, and had to be destroyed (all such missiles are equipped with explosives for this, that can be set off by remote control), the debris could come down on people. The Russian silos are in more isolated areas, and Russians are more tolerant of their government showering them with missile debris.
I’m not sure if the Russian people are actually “more tolerant” of being showered with missile debris. I think it probably has more to do with the official complaint procedure in Russia being more painful than being showered with missile debris.
Pic from the Vandenberg web site. Click for larger version.