i'm a lift operator...it takes around 18feet if yur traveling at 450fpm for an emergency stop. there are no sudden stops. and we haven't had a person fall off a chair unintentionally in 4 years.
allsportb10 - you've obviously never been to the pila world cup track, they used to stop dead pretty much there and you'd swing so far round. i think they changed it now though, it didnt seem so bad this year.