Well, gee, who did the actions that got him in jail? You? Your husband? Santa Claus? Oh, no, it must have been the Tooth Fairy ... you know, the one who forgot to leave Tink some money!
Sounds like he's learned very little. He definitely has the "poor me" card down well. He's doing an excellent job of making you feel guilty and he's obviously taking no responsibility.
Was the dump in the middle of nowhere his only choice of a place to live? Does he have a bike at home? If so, give him his old bike. It is a legal means of transportation. Heck, you might even want to consider buying him a good used one if he doesn't have one. Walking really is an option. Many people do it even today and not just for exercise even though that would be an added benefit. It may mean that he has to get moving 3 hours before an appointment, but that's the way it is when you live in the boonies and have no transportation. If he were my son, I might (and the operative word is MIGHT depending on how much he is willing to accept his responsibility in his plight) be willing to take him home after any meetings, but daylight things are his responsibility.
You shouldn't have to take off from work. Heck, you shouldn't even have to take him when you get done teaching. You deserve a break and some down time before going home and doing all the chores teaching entails. Plus, you have a wedding to plan, a house to run, a family that needs you. He's an adult living on his own.