I've done the "breaking away" UPS truck draft roll out. I was surprised how easy it was - stayed with the semi until well over 50mph - but started getting scared not being able to see pavement more than ten feet ahead under the trailer.

I've also hit 53mph - trying as hard as I could - on an Ozark county two lane road. (retrying several times)

I'm always skeptical if anyone says they went 60 or more - wind resistance really over powers gravity at about 50 - I weighed about 155 - but i guess some big guy could go faster? Anybody?