My first thought was: speeds like that ought to involve enough G-force to severely inhibit the ability of attendants to serve you en route...

...but then, didn't the Concorde break the sound barrier while en route?

I'm stuck in the 1950's -- I can't get it out of my head that one would need to wear a pressure suit while doing such things. :)

Hmmm... the Orient Express, with pressure suits... it would probably look like something between the stewardess from 2001, and Cat from Red Dwarf...

Reminds me of something which I can't quite put my finger on about people thinking at one point that any travel faster than x#mph wouldn't be possible for human beings because it would damage them. I believe that number was somewhere between a horse's sprint speed and top speed of low/low/low end cars today.

Anyone?

"They had a man at the front with a red flag," said Ligur.

"They've come on a bit since then, I reckon."

~ Good Omens