How long do Felony DUI cases generally last?

Hi, just wondering, how long do Felony DUI cases usually last? Specifically juvenile cases? I know a family friend who is going through the motions of the court process right now but have still not reached a solution after 10 months! The crux of the case is whether or not the injuries of the victims are serious enough to constitute a felony DUI, and after 10 months the DA has no conclusive evidence of any serious injuries, and yet the case keeps on continuing. My friend obviously is fighting for a reduced charge of a felony DUI. It seems as though his lawyer is simply milking the case which is costing my friend a fortune. Any body have any knowledge on this?