Well, on Alpengeist these predrop breaks are used frequently...unfortunately. They began being used around 1999 or so. They seem to be used to keep the forces in the cobra roll down on Alp. I remember the good old days sitting in the back seat of Alpengeist and getting unbelievable sensations going thru the cobra roll cuz of the G forces. Rarely is that "holding break" off anymore unfortunately, so Alpengeist has been MUCH tamer ever since, but still a great ride. If anyone remembers reading about Alpengeist breaking BOTH of someones legs with a preexisting condition "weak bones" you may understand one of the reasons they actually use this break on Alpengeist. It is possible, I will say, that it is used for evac purposes, but i tend not to think so. That break was on so hard for so much of this year, and it would ALMOST stop, and on empty trains it briefly would stop. I think it is maily used to "castrate" the ride. Maybe Alpengeist goes faster than designed, as has been the rumored case since it opened around the Williamsburg-Norfolk area. If you look at it, this holding break takes 10-15 feet or maybe even more off the total "freefall" drop when you watch the ride from the carousel area. It probably also reduces wear and tear and is probably a cost cutting method. Kinda like the way Alpengeist used to rip thru the 2nd half, and is now slowed much more by the mid course breaks.