I'm contemplating getting on a plane for an international flight, and I am not very soothed by the claims that planes are by far the safest form of travel, when I find that those claims rely on a "per passenger mile" comparison of various modes of travel. (After all, "per passenger mile", the Space Shuttle is the safest form of transportation, isn't it?)

I'd like to know what anyone with a detailed knowledge of the "driving vs. flying" safety statistics thinks about what Mary Schiavo (Former Inspector General of the U.S. Dept. of Transportation) had to say about this in her book "Flying Blind, Flying Safe" (p. 210):

"For years I had heard the FAA excuse planeloads of dead people because the body count for cars was higher in overall numbers. I had found studies and statistics that pointed out that the plane was safer than the car if you compared them on a per mile basis. If you look at them on a per trip basis, the CAR is safer. It only makes sense. It can take thirty or fifty miles for a plane just to get up to cruising altitude, and most car accidents happen less than twenty-five miles from home. Nope, per mile is misleading, slanted, and inaccurate."

Is it really true that "per trip", a car is safer than a plane? If so, how much safer?