No doubt I didn't express myself well. The only high-speed rail in any significant way in the U.S. is in the northeast corridor. The majority, by far, of the northeast corridor is dedicated to passenger. There is a section of about 30 miles, from Perryville, Maryland, to Baltimore, that has a considerable amount of freight on it. There are very limited amounts of freight elsewhere in the corridor. Much of the northeast corridor has triple or in some cases four tracks. They keep the freight off to the side and focus their attention and maintenance on the two inside tracks for the high-speed trains. That's the only place they're really running.
You're absolutely right. Amtrak does run on freight lines. They typically run at 79 miles an hour, with the exception of those territories where they have cab signalling--I don't want to get technical here--which is a sort of rudimentary form of positive train control. They run at 90 miles per hour, I believe.