When American's think of high speed rail, Amtrak's Acela Express is the closest they can get.
With a top speed of 150 mph, according to Amtrak, the Acela is indeed the fastest train currently running in the USA. 
However, frequent stops and the older, curving track limit the average speed of a trip from New York to Washington, DC to 80 mph, according to Railway Technology.
But what about rail travel outside the US?