Bad judgement in driving a car makes them a criminal? Stupid maybe, okay, but a criminal for a stupid mistake without malice? Forgetaboutit.
Yes. That's the difference between murder (dead body - malice intended) and manslaughter (dead body - no malice intended but negligence involved). If you drive your car in such a manner as to negligently cause the death (or potential death) of someone, then you are a criminal. If you are following all the driving laws and cause the death of someone, you are unlikely to be charged with anything as it was probably truly an accident that you could not have prevented by doing something so basic as following the law.
of course, the standard should be malice or negligence - DUI, street racing, etc. 18MPH over the limit is not negligence. hell, on a 55MPH highway, the typical speed is 70MPH (even in the rain) - that's 15 over the limit right there. that would mean that any driver getting into a crash resulting in injuries under those conditions should face jail time. its ridiculous.
Bad judgment that results in injury, death or property damage is charged as "Criminal Negligence."