Hello blind justice,
There is no way of knowing whether they would actually put him in jail, but since this is amnesty month, the whole point is that you can come forward freely and take care of your tickets. He will undoubtedly has to explain himself, and I don't think it's out of line to think he might spend overnight or a few more days in jail, but as I said--it's amnesty. I have represented people that have let these really rather minor things, get bigger and bigger and were afraid to go to court.
But it's never as bad as it seems. And if he wants his license back, there is no other way. If he feels better, he could take an attorney. He needs to go to court and they will set a time for him to come back and appear in front of a judge to answer the charges. He will probably want to plead guilty (most people do in a traffic court) and pay the fine. Of course if he is innocent he will maintain a not guilty plea and then just put his story and evidence to a judge to decide.
I assure you, it will not be as bad as he has imagined. Believe it or not, they want these things to "go away" so they can attend to the real problems of crime. Good luck to you both.
Lawyer (JD)
Juris Doctorate Degree