Re: Not only for fatalities
Here (California), driving under the speed limit can be considered impeding the flow of traffic. Driving while exhausted can be prosecuted as impaired driving. Riding a bicycle (skating, on horseback, whatever) in a manor that could cause injury can be considered reckless driving. Paying zero attention to road markings/signs on a bicycle (blades, horse-drawn vehicle, whatever) can be the same offense as if committed in an automobile.
All are ticketable, and if you're convicted are considered moving violations (points on license, insurance rates go up, etc.).
Most of the time, you'll only get cited if you're a complete ass to an officer after getting pulled over. Usually, they'll let you go with a warning (or release you to the custody of parent/guardian) ... and in the case of being too tired, they'll suggest running around your vehicle a couple times (or the equivalent) to wake up a bit, and then pulling over at the next safe spot to take a nap before carrying on (this last one happened to me as a newly licensed teenager ...).