Criminal Law Questions? Ask a Criminal Lawyer.
Does your son have a lawyer?
Do you know what the court order says about him being present in court?
What, exactly, is the court appearance for on the 4th? Initial appearance?
He does not have a lawyer. Can't afford it. The ticket says must personally appear in court.
Your son needs to send a "kite" (written request) to the director of the detention center and explain that he must appear in court on that day. Also, he should send something over to the courthouse to the attention of the traffic court clerk, telling where he is. Someone from the courthouse can call and have him brought to court, but first, they have to know where he is.
You should try to be there if you can. If he doesn't show up, tell the judge or other court official.
I don't see how a driving charge can be "rolled over" into a person felony anyway. A person felony is something like assault or sexual abuse.